Dithiocarbonate containing polyols as polymer polyol stabilizers

ABSTRACT

This invention relates to novel macromers containing dithiocarbonate (or xanthate) groups, novel preformed stabilizers comprising macromers, and novel polymer polyols comprising the novel macromers and/or novel preformed stabilizers. This invention also relates to processes for the preparation of these materials. Other aspects of this invention include foams comprising the novel polymer polyols and a process for preparing foam comprising the novel polymer polyols.

FIELD OF INVENTION

This invention relates to novel macromers, novel preformed stabilizerscomprising the novel macromers, novel polymer polyols comprising thenovel macromers or the novel preformed stabilizers, and to processes forthe preparation of these materials. This invention also relates to foamsprepared from these novel polymer polyols and to a process of preparingthese foams.

BACKGROUND

Polymer polyols, also known as filled polyols, are viscous fluidscomprising fine particles dispersed in polyols. Examples of solids usedinclude styrene-acrylonitrile co-polymers and polyureas. The solids aretypically prepared by in situ polymerization of ethylenicallyunsaturated monomers in the base polyol. Polymer polyols are commonlyused for the production of polyurethane foams, and particularly flexiblepolyurethane foams.

Macromers are known and have been used to stabilize polymer polyols byco-polymerization with one or more ethylenically unsaturated monomers(such as, for example, styrene and acrylonitrile). Because ofsimilarities in chemical composition, the polyether tail(s)energetically favor association with the polyol molecules in thecontinuous phase rather than with the styrene-acrylonitrile co-polymer.The polyether tails extend into the continuous phase, thereby forming a“brush” layer near the particle-fluid interface which screens theattractive van der Waals forces between particles. This phenomenon isknown as steric stabilization. In order to form a brush layer whicheffectively screens van der Waals forces several conditions must be met.The polyether tails must be similar in chemical composition to thecontinuous phase so that they fully extend into the continuous phase anddo not adsorb to the particles. Also, the surface coverage and molecularweight must be high enough so that the interfacial brush layer issufficiently thick to prevent agglomeration of the solid particles.

It is known that large, bulky molecules are effective macromers becauseless material can be used to sterically stabilize the particles.Generally speaking, this is due to the fact that a highly branchedpolymer has a considerably larger excluded volume than a linear molecule(such as, e.g., a monol), and therefore less of the branched polymer isrequired. Coupling multi-functional polyols with polyisocyanates is alsoknown and described in the field of polymer polyols as a suitable meansto increase the molecular weight of the macromer.

Preformed stabilizers (PFS) are known to be useful for preparing polymerpolyols having a lower viscosity at a high solids content. In general, apreformed stabilizer is an intermediate obtained by reacting a macromerwhich contains reactive unsaturation (e.g. acrylate, methacrylate,maleate, etc.) with a monomer (i.e. acrylonitrile, styrene, methylmethacrylate, etc.), optionally in a diluent or a solvent (i.e.methanol, isopropanol, toluene, ethylbenzene, polyether polyols, etc.)to give a co-polymer (dispersion having e.g. a low solids content (e.g.<20%), or soluble grafts, etc.). Thus, in the preformed stabilizerprocess, a macromer is reacted with monomers to form a co-polymercomposed of macromer and monomers. These co-polymers comprising amacromer and monomers are commonly referred to as preformed stabilizers(PFS). Reaction conditions may be controlled such that a portion of theco-polymer precipitates from solution to form a solid. In manyapplications, a dispersion having a low solids content (e.g., 3 to 15%by weight) is obtained. Preferably, the reaction conditions arecontrolled such that the particle size is small, thereby enabling theparticles to function as “seeds” in the polymer polyol reaction.

It has surprisingly been found that, by incorporating carbon disulfideinto the molecule during the polyether polyol synthesis, the resultingdithiocarbonate (or xanthate) group can reduce or eliminate the amountof reactive unsaturation which is necessary in the macromer in order forthe macromer to be effective in stabilizing polymer polyols and/or informing preformed stabilizers for polymer polyols.

SUMMARY OF THE INVENTION

This invention relates to macromers containing dithiocarbonate (orxanthate) functionality. These macromers comprise the reaction productof:

-   (a) a polyether dithiocarbonate polyol having an equivalent weight    of 230 Da to 5600 Da, and functionality of 1 to 8, having a    dithiocarbonate content of from 0.05% to 20% by weight, and which    comprises the copolymerization product of a reaction mixture    comprising:    -   (i) one or more starter polyether polyols having an equivalent        weight less than 1000 Da, an OH number greater than 56 mg KOH/g        polyol, and a functionality of 1 to 8,    -   (ii) one or more alkylene oxides,    -   and    -   (iii) carbon disulfide,    -   in the presence of    -   (iv) an alkoxylation catalyst;-   with-   (b) an ethylenically unsaturated compound containing hydroxyl    reactive groups;-   optionally, in the presence of-   (c) at least one catalyst.

The invention also relates to a process for preparing these macromers.This process comprises:

-   (1) reacting    -   (a) a polyether dithiocarbonate polyol having an equivalent        weight of 230 Da to 5600 Da, and functionality of 1 to 8, having        a dithiocarbonate content of from 0.05% to 20% by weight, and        which comprises the copolymerization product of a reaction        mixture comprising:        -   (i) one or more starter polyether polyols having an            equivalent weight less than 1000 Da, an OH number greater            than 56 mg KOH/g polyol, and a functionality of 1 to 8,        -   (ii) one or more alkylene oxides,        -   and        -   (iii) carbon disulfide,        -   in the presence of        -   (iv) an alkoxylation catalyst;    -   with    -   (b) an ethylenically unsaturated compound containing hydroxyl        reactive groups;    -   optionally, in the presence of    -   (c) at least one catalyst.

This invention also relates to preformed stabilizers. These preformedstabilizers comprise the free-radical polymerization product of:

-   (1) a macromer which comprises the reaction product of    -   (a) a polyether dithiocarbonate polyol having an equivalent        weight of 230 Da to 5600 Da, and functionality of 1 to 8, having        a dithiocarbonate content of 0.05% to 20% by weight, and which        comprises the copolymerization product of a reaction mixture        comprising        -   (i) one or more starter polyether polyols having an            equivalent weight less than 1000 Da, an OH number greater            than 56 mg KOH/g polyol, and a functionality of 1 to 8,        -   (ii) one or more alkylene oxides,        -   and        -   (iii) carbon disulfide,        -   in the presence of        -   (iv) an alkoxylation catalyst;    -   optionally, with    -   (b) an ethylenically unsaturated compound containing hydroxyl        reactive groups;    -   optionally, in the presence of    -   (c) at least one catalyst;-   with-   (2) at least one ethylenically unsaturated monomer;-   in the presence of-   (3) at least one free-radical polymerization initiator;-   and, optionally,-   (4) a liquid diluent;-   and, optionally,-   (5) a polymer control agent.

The invention also relates to a process for preparing preformedstabilizers. This process comprises:

-   (A) free-radically polymerizing    -   (1) a macromer which comprises the reaction product of:        -   (a) a polyether dithiocarbonate polyol having an equivalent            weight of 230 Da to 5600 Da, and a functionality of 1 to 8,            having a dithiocarbonate content of 0.05% to 20% by weight,            and which comprises the copolymerization product of a            reaction mixture comprising:            -   (i) one or more starter polyether polyols having an                equivalent weight less than 1000 Da, an OH number                greater than 56 mg KOH/g polyol, and a functionality of                1 to 8,            -   (ii) one or more alkylene oxides,            -   and            -   (iii) carbon disulfide,            -   in the presence of            -   (iv) an alkoxylation catalyst;        -   optionally, with        -   (b) an ethylenically unsaturated compound containing            hydroxyl reactive groups;        -   optionally, in the presence of        -   (c) at least one catalyst;    -   with    -   (2) at least one ethylenically unsaturated monomer;    -   in the presence of    -   (3) at least one free-radical polymerization initiator;    -   and, optionally,    -   (4) a liquid diluent;    -   and, optionally,    -   (5) a polymer control agent.

This invention is also directed to a polymer polyol. The polymer polyolsof the invention comprise the in-situ, free-radical polymerizationproduct of:

-   (A) a base polyol;-   (B) a component comprising at least one of:    -   (1) a macromer containing dithiocarbonate functionality that        comprises the reaction product of: (a) a polyether        dithiocarbonate polyol having an equivalent weight of 230 Da to        5600 Da, and functionality of 1 to 8, having a dithiocarbonate        content of from 0.05% to 20% by weight, and which comprises the        copolymerization product of a reaction mixture comprising (i)        one or more starter polyether polyols having an equivalent        weight less than 1000 Da, an OH number greater than 56 mg KOH/g        polyol, and a functionality of 1 to 8, (ii) one or more alkylene        oxides, and (iii) carbon disulfide, in the presence of (iv) an        alkoxylation catalyst; optionally, with (b) an ethylenically        unsaturated compound containing hydroxyl reactive groups; and        optionally, in the presence of (c) at least one catalyst;    -   and    -   (2) a preformed stabilizer that comprises the free-radical        polymerization product of: (1) a macromer which comprises the        reaction product of: (a) a polyether dithiocarbonate polyol        having an equivalent weight of 230 Da to 5600 Da, and        functionality of 1 to 8, having a dithiocarbonate content of        0.05% to 20% by weight, and which comprises the copolymerization        product of a reaction mixture comprising (i) one or more starter        polyether polyols having an equivalent weight less than 1000 Da,        an OH number greater than 56 mg KOH/g polyol, and a        functionality of 1 to 8, (ii) one or more alkylene oxides,        and (iii) carbon disulfide, in the presence of (iv) an        alkoxylation catalyst; with, optionally, (b) an ethylenically        unsaturated compound containing hydroxyl reactive groups; and        optionally, in the presence of (c) at least one catalyst;        with (2) at least one ethylenically unsaturated monomer, in the        presence of (3) at least one free-radical polymerization        initiator, and, optionally, (4) a liquid diluent, and,        optionally (5) a polymer control agent;-   and-   (C) at least one ethylenically unsaturated monomer;-   in the presence of-   (D) at least one free-radical polymerization initiator;-   and, optionally,-   (E) a polymer control agent.

This invention also relates to a process for preparing these polymerpolyols. This process comprises:

-   (I) free-radically polymerizing:    -   (A) a base polyol;    -   (B) a component comprising at least one of:        -   (1) a macromer containing dithiocarbonate functionality that            comprises the reaction product of: (a) a polyether            dithiocarbonate polyol having an equivalent weight of 230 Da            to 5600 Da, and functionality of 1 to 8, having a            dithiocarbonate content of from 0.05% to 20% by weight, and            which comprises the copolymerization product of a reaction            mixture comprising (i) one or more starter polyether polyols            having an equivalent weight less than 1000 Da, an OH number            greater than 56 mg KOH/g polyol, and a functionality of 1 to            8, (ii) one or more alkylene oxides, and (iii) carbon            disulfide, in the presence of (iv) an alkoxylation catalyst;            optionally, with (b) an ethylenically unsaturated compound            containing hydroxyl reactive groups; and optionally, in the            presence of (c) at least one catalyst;        -   and        -   (2) a preformed stabilizer that comprises the free-radical            polymerization product of: (1) a macromer which comprises            the reaction product of: (a) a polyether dithiocarbonate            polyol having an equivalent weight of 230 Da to 5600 Da, and            functionality of 1 to 8, having a dithiocarbonate content of            0.05% to 20% by weight, and which comprises the            copolymerization product of a reaction mixture            comprising (i) one or more starter polyether polyols having            an equivalent weight less than 1000 Da, an OH number greater            than 56 mg KOH/g polyol, and a functionality of 1 to 8, (ii)            one or more alkylene oxides, and (iii) carbon disulfide, in            the presence of (iv) an alkoxylation catalyst; with,            optionally, (b) an ethylenically unsaturated compound            containing hydroxyl reactive groups; optionally, in the            presence of (c) at least one catalyst; with (2) at least one            ethylenically unsaturated monomer, in the presence of (3) at            least one free-radical polymerization initiator, and,            optionally, (4) a liquid diluent, and, optionally (5) a            polymer control agent;    -   (C) at least one ethylenically unsaturated monomer;    -   in the presence of    -   (D) at least one free-radical polymerization initiator;    -   and, optionally,    -   (E) a polymer control agent.

This invention also relates to foams comprising these polymer polyols.These foams comprise the reaction product of: (I) a diisocyanate orpolyisocyanate component, with (II) an isocyanate-reactive componentcomprising the polymer polyol described above, in the presence of (III)a catalyst, (IV) a blowing agent, and (V) a surfactant.

The invention also relates to a process for preparing foams. Thisprocess comprises reacting (I) a diisocyanate or polyisocyanatecomponent, with (II) an isocyanate-reactive component comprising thepolymer polyol described above, in the presence of (III) a catalyst,(IV) a blowing agent, and (V) a surfactant.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described for purposes of illustrationand not limitation. Except in the operating examples, or where otherwiseindicated, all numerical parameters are to be understood as beingprefaced and modified in all instances by the term “about”, in which thenumerical parameters possess the inherent variability characteristic ofthe underlying measurement techniques used to determine the numericalvalue of the parameter. Examples of such numerical parameters include,but are not limited to OH numbers, equivalent and/or molecular weights,functionalities, amounts, percentages, etc. At the very least, and notas an attempt to limit the application of the doctrine of equivalents tothe scope of the claims, each numerical parameter described in thepresent description should at least be construed in light of the numberof reported significant digits and by applying ordinary roundingtechniques.

Also, any numerical range recited herein is intended to include allsub-ranges subsumed within the recited range. For example, a range of “1to 10” is intended to include all sub-ranges between (and including) therecited minimum value of 1 and the recited maximum value of 10, that is,having a minimum value equal to or greater than 1 and a maximum valueequal to or less than 10. All end points of any range are includedunless specified otherwise. Any maximum numerical limitation recited inthis specification is intended to include all lower numericallimitations subsumed therein and any minimum numerical limitationrecited in this specification is intended to include all highernumerical limitations subsumed therein. Accordingly, Applicant reservesthe right to amend this specification, including the claims, toexpressly recite any sub-range subsumed within the ranges expresslyrecited herein. All such ranges are inherently described in thisspecification such that amending to expressly recite any such sub-rangeswould comply with the requirements of 35 U.S.C. § 112 and 35 U.S.C. §132(a).

The grammatical articles “a”, “an”, and “the”, as used herein, areintended to include “at least one” or “one or more”, unless otherwiseindicated, even if “at least one” or “one or more” is used in certaininstances. By way of example, and without limitation, “a component”means one or more components, and thus, possibly, more than onecomponent is contemplated and may be employed or used in animplementation of the described embodiments. Further, the use of asingular noun includes the plural, and the use of a plural noun includesthe singular, unless the context of the usage requires otherwise.

Equivalent weights and molecular weights given herein in Daltons (Da)are number average equivalent weights and number average molecularweights respectively, unless indicated otherwise, and were determined byGPC as described herein.

The number average and weight average, Mn and Mw, respectively,molecular weights herein were determined by gel-permeationchromatography (GPC) using a method based on DIN 55672-1, employingchloroform as the eluent with a mixed bed column (Agilent PL Gel; SDVB;3 micron Pore diameter: 1×Mixed-E+5 micron Pore diameter: 2×Mixed-D),refractive index (RI) detection and calibrated with polyethylene glycolas the standard.

Isocyanate index is the relative stoichiometric amount of isocyanatefunctional groups necessary to react with the isocyanate reactive groupspresent in the overall foam formulation. It is expressed as a percentagein this application; thus equal stoichiometric amounts of isocyanatefunctional groups and isocyanate reactive functional groups in theformulation results in an isocyanate index of 100%.

The term “monomer” means the simple unpolymerized form of a chemicalcompound having relatively low molecular weight, e.g., acrylonitrile,styrene, methyl methacrylate, and the like.

The phrase “polymerizable ethylenically unsaturated monomer” means amonomer containing ethylenic unsaturation (>C═C<, i.e. two double bondedcarbon atoms) that is capable of undergoing free radically inducedaddition polymerization reactions.

The term preformed stabilizer is defined as an intermediate obtained byreacting a macromer containing reactive unsaturation (e.g. acrylate,methacrylate, maleate, etc.) with one or more monomers (i.e.acrylonitrile, styrene, methyl methacrylate, etc.), with and at leastone free radical initiator, in the presence of a polymer control agent(PCA) and, optionally, in a diluent, to give a co-polymer (i.e. adispersion having e.g. a low solids content (e.g. <30%), or solublegrafts, etc.).

The term “stability” means the ability of a material to maintain astable form such as the ability to stay in solution or in suspension.Polymer polyols having good stability generally also have goodfilterability.

The phrase “polymer polyol” refers to such compositions which can beproduced by polymerizing one or more ethylenically unsaturated monomersdissolved or dispersed in a polyol in the presence of a free radicalcatalyst to form a stable dispersion of polymer particles in the polyol.These polymer polyols have the valuable property, for example, thatpolyurethane foams and elastomers produced therefrom exhibit higherload-bearing properties than are provided by the correspondingunmodified polyols.

As used herein, the phrase “polyol feed” refers to the amount of basepolyol feed present in the polymer polyol or present in the process ofpreparing the polymer polyol.

As used herein, the phrase “total feed” refers to the sum of allquantities of components present in each of the various products (i.e.,preformed stabilizers, polymer polyols, etc.) and/or present in theprocess of preparing each of the various products. The total solidslevels (i.e., weight percent of polyacrylonitrile and polystyrene) ofthe polymer polyols were measured by an analytical technique known asnear-infrared (NIR) spectroscopy. The specific NIR measurement of totalsolids is a variation on ASTM D6342-12, “Polyurethane Raw Materials:Determining Hydroxyl Number of Polyols by Near Infrared (NIR)Spectroscopy”. The variations used include (1) substitution of theabsorption bands associated with polyacrylonitrile and polystyreneinstead of those associated with hydroxyl number, and (2) acquiring theNIR spectra in reflection mode rather than transmission mode. The use ofreflection mode is due to polymer polyols being opaque, and thus arescattering materials with respect to infrared radiation. Measurement ofthe NIR spectra in reflection mode results in higher quality spectra forcalibration and measurement purposes as PMPOs reflect more NIR radiationthan they transmit. Calibrations to be used as standards were developedin accordance with ASTM D6342-12. In addition, the absorption bandsassociated with polyacrylonitrile and polystyrene are used to calculatethe weight ratio of styrene:acrylonitrile in the total polymer. Oneskilled in the art will recognize that this is an analyticalconfirmation of the main mechanism for controlling the S/AN ratio, whichis the wt. % of monomers in the total reactor feed.

Hydroxyl numbers or OH numbers were determined according to ASTMD4274-11, and are reported in mg[KOH]/g[polyol].

As used herein “viscosity” is in millipascal-seconds (mPa·s) measured at25° C. The viscosity was measured on an Anton Paar SVM3000 viscometer at25° C. that has been demonstrated to give equivalent results as can begenerated with ASTM-D4878-15. The instrument was calibrated usingmineral oil reference standards of known viscosity.

As used herein, the term dithiocarbonate content refers to xanthatefunctionality of the polyether polyol. The xanthate functionality canparticipate in a “living polymerization” process.

The dithiocarbonate content was determined by dissolving the sample indeuterated chloroform and run on a 400 MHz nuclear magnetic resonance(NMR) (a Varian MR400) spectrometer employing high-resolution ¹H-NMR forcharacterization.

The macromers of the invention include compounds which comprise thereaction product of: (a) a polyether dithiocarbonate polyol having anequivalent weight of 230 Da to 5600 DA, a functionality of 1 to 8, andhaving a dithiocarbonate content of from 0.05% to 20% by weight, basedon the total weight of the polyether polyol.

These polyether dithiocarbonate polyols may have an equivalent weight ofat least about 230 Da, or of at least about 280 Da, or of at least about330 Da. The equivalent weight of these polyether polyols may be 5600 Daor less, or 5400 Da or less, or 5200 Da or less. These polyether polyolsmay have an equivalent weight ranging between any combination of theseupper and lower values, inclusive, such as, for example, from at leastabout 230 Da to about 5600 Da or less, or from at least about 280 Da toabout 5400 Da or less, or from at least about 330 Da to about 5200 Da orless.

The functionality of these polyether dithiocarbonate polyols may be atleast about 1, or at least about 2, or at least about 3. Thefunctionality of these polyether polyols may also be 8 or less, or 7 orless, or 6 or less. In general, these polyether polyols may have afunctionality ranging between any combination of these upper and lowervalues, inclusive, such as, for example, from at least about 1 to about8 or less, or from at least about 2 to about 7 or less, or from at leastabout 3 to about 6 or less.

These polyether dithiocarbonate polyols may have a dithiocarbonatecontent of at least about 0.05% by weight, or of at least about 0.10% byweight, or of at least about 0.15% by weight. The dithiocarbonatecontent of these polyether polyols may be 20% by weight or less, or 15%by weight or less, or 10% by weight or less. These polyetherdithiocarbonate polyols may have a dithiocarbonate content rangingbetween any combination of these upper and lower values, inclusive, suchas, for example, from at least about 0.05% by weight to about 20% byweight or less, or from at least about 0.10% to about 15% by weight orless, or from at least about 0.15% to about 10% by weight or less, basedon 100% by weight of the polyether polyol.

These dithiocarbonate containing polyether polyols comprise thecopolymerization product of a reaction mixture which comprises: (i) oneor more starter polyether polyols having an equivalent weight less than1000 Da, an OH number greater than 56 mg KOH/g polyol, and afunctionality of 1 to 8, (ii) one or more alkylene oxides, and (iii)carbon disulfide, in the presence of (iv) an alkoxylation catalyst.

Suitable starter polyether polyols (i) have an equivalent weight lessthan or equal to 1000 Da, or less than or equal to 500 Da, or less thanor equal to 250 Da. The equivalent weight of the starter polyetherpolyols is also typically at least 30 Da, or at least 100 Da, or atleast 150 Da. The suitable starter polyether polyols will, in general,have an equivalent weight ranging between any combination of these upperand lower values, inclusive, such as, for example, of 30 Da to less thanor equal to 1000 Da, or 100 Da to less than or equal to 500 Da, or 150Da to less than or equal to 250 Da.

The starter polyether polyols (i) may have an OH number of at least 56mg KOH/g polyol, or at least 112 mg KOH/g polyol, or at least 220 mgKOH/g polyol. These starter polyether polyols may also have an OH numberless than or equal to 1850 mg KOH/g polyol, or less than or equal to 560mg KOH/g polyol or less than or equal to 400 mg KOH/g polyol. Ingeneral, the starter polyether polyols (i) will have an OH numberranging between any combination of these upper and lower values,inclusive, such as, for example, of at least 56 mg KOH/g polyol to lessthan or equal to 1850 mg KOH/g polyol, or at least 112 mg KOH/g polyolto less than or equal to 560 mg KOH/g polyol, or at least 220 mg KOH/gpolyol to less than or equal to 400 mg KOH/g polyol.

The functionality of these starter polyether polyols (i) may be at leastabout 1, or at least about 2, or at least about 3. The functionality ofthese starter polyether polyols (i) may also be 8 or less, or 7 or less,or 6 or less. In general, these starter polyether polyols (i) may have afunctionality ranging between any combination of these upper and lowervalues, inclusive, such as, for example, from at least about 1 to about8 or less, or from at least about 2 to about 7 or less, or from at leastabout 3 to about 6 or less.

Suitable starter polyether polyols include, for example, polyoxyethylenemonols, glycols, triols, tetrols and higher functionality polyols,polyoxypropylene monols, glycols, triols, tetrols and higherfunctionality polyols, mixtures thereof, etc. When mixtures of alkyleneoxides are used, the ethylene oxide and propylene oxide, for example,may be added simultaneously or sequentially to provide internal blocks,terminal blocks or random distribution of the oxyethylene groups and/oroxypropylene groups in the polyether polyol. Suitable starters orinitiators for these polyether polyols include, for example, 1-butanol,ethylene glycol, propylene glycol, diethylene glycol, dipropyleneglycol, tripropylene glycol, trimethylolpropane, glycerol,pentaerythritol, sorbitol, sucrose, ethylenediamine, toluene diamine,etc. Suitable alkylene oxides include ethylene oxide, propylene oxide,butylene oxide, styrene oxide, etc. By alkoxylation of the starter, asuitable starter polyether polyol can be formed. The suitable starterpolyether polyols are free of dithiocarbonate groups.

Suitable alkylene oxides to be reacted with the starter polyetherpolyols include, for example, ethylene oxide, propylene oxide, butyleneoxide, styrene oxide, epichlorohydrin, etc. In an embodiment of theinvention, the alkylene oxides comprise ethylene oxide, propylene oxideand/or mixtures thereof. When used as a mixture, the ethylene oxidecontent can vary from 2% to 50% by weight of the total oxide feed, andcan be utilized as a block, a random co-feed, or as a “cap” to give highprimary hydroxyl containing polyols.

Carbon disulfide is also reacted with the starter polyether polyols andalkylene oxides in the present of an alkoxylation catalyst to form thepolyether polyols useful as macromers in accordance with the presentinvention.

Suitable alkoxylation catalysts (iv) to be used to obtain the polyetherdithiocarbonate polyols (a) include catalysts such as, basic catalystsincluding, for example, potassium hydroxide, sodium hydroxide, cesiumhydroxide, etc., and double metal cyanide catalysts including amorphousand non-amorphous DMC catalysts.

Suitable ethylenically unsaturated compounds containing hydroxylreactive groups to be used as component (b) of the macromers include,for example, methyl methacrylate, ethyl methacrylate, maleic anhydride,3-isopropenyl-α,α-dimethyl benzyl isocyanate, 2-isocyanatoethylmethacrylate, adducts of isophorone diisocyanate and 2-hydroxyethylmethacrylate, adducts of toluenediisocyanate and 2-hydroxypropylacrylate, etc.

Suitable catalysts (c) for the macromers herein include virtually anycatalyst known to be suitable for urethane reactions can be used ascomponent (c) in the present invention. Suitable polyurethane catalystsare well known in the art; an extensive list appears in U.S. Pat. No.5,011,908, the disclosure of which is herein incorporated by reference.Suitable organotin catalysts include tin salts and dialkyltin salts ofcarboxylic acids. Examples include stannous octoate, dibutyltindilaurate, dibutyltin diacetate, stannous oleate, and the like. Alsocatalysts such as bismuth(III)neodecanoate.

In the process for preparing the macromer, the polyether dithiocarbonatepolyol (a) is typically reacted optionally, with (b) the ethylenicallyunsaturated compound containing hydroxyl reactive groups, optionally, inthe presence of (c) at least one catalyst, at temperatures of about 25°C. to about 250° C. for time periods of from about 1 to about 10 hours.It is preferred that this reaction is at temperatures of about 60° C. toabout 200° C. for a time of from about 2 to about 7 h ours.

The preformed stabilizers herein comprise the free-radicalpolymerization product of: (1) a macromer as described herein, with (2)at least one ethylenically unsaturated monomer, in the presence of (3)at least one free-radical polymerization initiator and, optionally, (4)a liquid diluent, and, optionally, (5) a polymer control agent.

With respect to the preformed stabilizers and to the process of makingthese in accordance with the present invention, the (1) macromers are asdescribed herein. In one embodiment, the macromers (1) may comprise (a)a polyether dithiocarbonate polyol having an equivalent weight of 230 Dato 5600 Da, a functionality of 1 to 8 and a dithiocarbonate content offrom 0.05 to 20% by weight, and which comprises the copolymerizationproduct of a reaction mixture comprising (i) one or more starterpolyether polyols having an equivalent weight less than 1000 Da, an OHnumber greater than 56 mg KOH/g polyol and functionality of 1 to 8, (ii)an alkylene oxide, with (iii) carbon disulfide, in the presence of (iv)an alkoxylation catalyst; optionally with (b) an ethylenicallyunsaturated compound containing hydroxyl reactive groups; optionally inthe presence of (c) a catalyst.

In one embodiment, the suitable ethylenically unsaturated compoundcontaining hydroxyl reactive groups for (b) in the macromer (1)comprises a compound selected from the group consisting of methylmethacrylate, ethyl methacrylate, maleic anhydride,3-isopropenyl-α,α-dimethyl benzyl isocyanate, 2-isocyanatoethylmethacrylate, adducts of isophorone diisocyanate and 2-hydroxyethylmethacrylate, adducts of toluenediisocyanate and 2-hydroxypropylacrylate, etc.

Suitable (2) ethylenically unsaturated monomers for the preformedstabilizers of the invention include, for example, aliphatic conjugateddienes such as butadiene and isoprene; monovinylidene aromatic monomerssuch as styrene, α-methylstyrene, (t-butyl)styrene, chlorostyrene,cyanostyrene and bromostyrene; α,β-ethylenically unsaturated carboxylicacids and esters thereof such as acrylic acid, methacrylic acid, methylmethacrylate, ethyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate,itaconic acid, maleic anhydride and the like; α,β-ethylenicallyunsaturated nitriles and amides such as acrylonitrile,methacrylonitrile, acrylamide, methacrylamide, N,N-dimethyl acrylamide,N-(dimethylaminomethyl)acrylamide and the like; vinyl esters such asvinyl acetate; vinyl ethers, vinyl ketones, vinyl and vinylidene halidesas well as a wide variety of other ethylenically unsaturated materialswhich are copolymerizable with the aforementioned monomeric adduct orreactive monomer. It is understood that mixtures of two or more of theaforementioned monomers are also suitably employed in making thepreformed stabilizer. Of the above monomers, the monovinylidene aromaticmonomers, particularly styrene, and the ethylenically unsaturatednitriles, particularly acrylonitrile are preferred.

When using a mixture of monomers, it is preferred to use a mixture oftwo monomers. These monomers are typically used in weight ratios of from80:20 (styrene:acrylonitrile) to 20:80 (S:AN), or from 75:25 (S:AN) to25:75 (S:AN).

Suitable free-radical polymerization initiators (3) for preformedstabilizer include, for example, peroxides including both alkyl and arylhydroperoxides, alkyl and aryl peroxides, peresters, persulfates,perborates, percarbonates, azo compounds, etc. Some specific examplesinclude catalysts such as hydrogen peroxide, di(t-butyl)-peroxide,t-butylperoxy diethyl acetate, t-butyl peroctoate, t-butyl peroxyisobutyrate, 1,1-di(t-butylperoxy)cyclohexane, t-butyl peroxy3,5,5-trimethyl hexanoate, t-butyl perbenzoate, t-butyl peroxy pivalate,t-amyl peroxy pivalate, t-butyl peroxy-2-ethyl hexanoate,1,1-di(t-amylperoxy)cyclohexane, lauroyl peroxide, cumene hydroperoxide,t-butyl hydroperoxide, azobis(isobutyronitrile), 2,2′-azobis-(2-methylbutyronitrile), etc.

Suitable catalysts concentrations range from about 0.01 to about 2% byweight, or from about 0.05 to 1% by weight, and or from 0.05 to 0.3% byweight, based on the total weight of the components (i.e. 100% by weightof the combined weight of the macromer, the ethylenically unsaturatedmonomer, the free-radical polymerization initiator and, optionally theliquid diluent and/or the chain transfer agent.

Suitable diluents (4) for the preformed stabilizers of the presentinvention include, for example, compounds such as monols (i.e.,monohydroxy alcohols), polyols, hydrocarbons, ethers etc., and mixturesthereof. Suitable monols include all alcohols which contain at least onecarbon atom, such as, for example, methanol, ethanol, n-propanol,isopropanol, n-butanol, sec.-butanol, tert-butanol, n-pentanol,2-pentanol, 3-pentanol, etc. and mixtures thereof. A preferred monol isisopropanol.

Suitable polyols to be used as a diluent (4) comprise, for example,poly(oxypropylene) glycols, triols and higher functionality polyols.Such polyols include poly(oxypropylene-oxyethylene) polyols; however,desirably the oxyethylene content should comprise less than about 50% ofthe total and, preferably less than about 30%. The ethylene oxide can beincorporated in any fashion along the polymer chain. Stated another way,the ethylene oxide can be either incorporated in internal blocks, asterminal blocks, or may be randomly distributed along the polymer chain.It is well known in the art that polyols contain varying amounts ofnon-induced unsaturation. The extent of unsaturation does not affect inany adverse way the formation of the polymer polyols in accordance withthe present invention.

For purposes of the present invention, useful polyols should have anumber average molecular weight of about 400 Da or greater, the numberaverage being used herein being the theoretical, hydroxyl number derivedvalue. The true number average molecular weight may be somewhat less,depending upon the extent to which the true molecular functionality isbelow the starting or theoretical functionality.

The polyols employed can have hydroxyl numbers which vary over a widerange. In general, the hydroxyl numbers of the polyols employed in theinvention can range from about 20 mg KOH/g polyol and lower, to about280 mg KOH/g polyol and higher. The hydroxyl number is defined as thenumber of milligrams of potassium hydroxide required for the completehydrolysis of the fully phthalated derivative prepared from 1 gram ofpolyol. The hydroxyl number can also be defined by the equation:

OH=(56.1×1000×f)/m.w.

where:

-   -   OH=hydroxyl number of the polyol;    -   f=functionality, that is, average number of hydroxyl groups per        molecule of the polyol;    -   and    -   m.w.=molecular weight of the polyol.

The exact polyol employed depends upon the end use of the polyurethaneproduct to be produced. The molecular weight or the hydroxyl number isselected properly to result in the desired foam processing and/orphysical properties when the polymer polyol produced from the polyol isconverted to a polyurethane. The polyols preferably possess a hydroxylnumber of from about 50 mg KOH/g polyol to about 150 mg KOH/g polyol forsemi-flexible foams and from about 25 mg KOH/g polyol to about 70 mgKOH/g polyol for flexible foams. Such limits are not intended to berestrictive, but are merely illustrative of the large number of possiblecombinations of the above polyol co-reactants.

Preferred polyol components to be used as diluents in the presentinvention typically include, for example, the alkylene oxide adducts ofsuitable starter materials having 4 or more hydroxyl groups such as, forexample, pentaerythritol, sorbitol, diether of sorbitol, mannitol,diether of mannitol, arabitol, diether of arabitol, sucrose, oligomer ofpolyvinyl alcohol or glycidol, mixtures thereof, etc.

When using a mixture of a monol and a polyol as the diluent for thepreformed stabilizer, the polyol preferably comprises only a minoramount of the diluent and the monol comprises a major amount. Ingeneral, the polyol will comprise less than 30 weight percent of thediluent, preferably less than about 20 weight percent, and mostpreferably less than about 15 weight percent. The amount of the polyolcomponent present in the diluent is below the concentration at whichgelling occurs in the preformed stabilizer.

Generally, the quantity of diluent is >40% by weight, based on 100% byweight of the PFS (preformed stabilizer).

Polymer control agents (5) may also be present in the preformedstabilizers of the present invention and the process of making thepreformed stabilizers. Suitable polymer control agents for this aspectof the present invention include, for example, isopropanol, ethanol,tert-butanol, toluene, ethylbenzene, triethylamine, dodecylmercaptan,octadecylmercaptan, carbon tetrachloride, carbon tetrabromide,chloroform, methylene chloride. Polymer control agents are also commonlyreferred to as molecular weight regulators. These compounds are employedin conventional amounts to control the molecular weight of thecopolymerizate.

Suitable processes for preparing the preformed stabilizers are similarto known methods described in, for example, U.S. Pat. Nos. 5,196,476,5,268,418, and 7,759,423, the disclosures of which are hereinincorporated by reference. In general, the process of preparing thepreformed stabilizer is similar to the process of preparing the polymerpolyol. The temperature range is not critical and may vary from about80° C. to about 150° C. or higher, and preferably from about 115° C. toabout 125° C. or so. The catalyst and temperature should be selectedsuch that the catalyst has a reasonable rate of decomposition withrespect to the hold-up time in the reactor for a continuous flow reactoror the feed time for a semi-batch reactor.

Mixing conditions employed in this process are obtained by using a backmixed reactor (e.g. a stirred flask or stirred autoclave). The reactorsof this type keep the reaction mixture relatively homogeneous and soprevent localized high monomer to macromer ratios such as occur intubular reactors, where all of the monomer is added at the beginning ofthe reactor. In addition, more efficient mixing can be obtained by theuse of an external pump around loop on the reactor section. Forinstance, a stream of reactor contents may be removed from the reactorbottom via external piping and returned to the top of the reactor (orvice versa) in order to enhance internal mixing of the components. Thisexternal loop may contain a heat exchanger if desired.

The combination of conditions selected for the preparation of thepreformed stabilizer should not lead to cross-linking or gel formationin the preformed stabilizer which can adversely affect the ultimateperformance in preparing the polymer polyol composition. Combinations oftoo low a diluent concentration, too high a precursor and/or monomerconcentration, too high a catalyst concentration, too long of a reactiontime, and too much unsaturation in the precursor can result inineffective preformed stabilizer from cross-linking or gelling.

Particularly preferred processes of preparing the preformed stabilizersherein are those as described in, for example, U.S. Pat. Nos. 5,196,476and 5,268,418, the disclosures of which are hereby incorporated byreference. Preferred diluents and relative concentrations, ethylenicallyunsaturated monomers and relative concentrations, free-radicalinitiators and relative concentrations, and process conditions set forthin the references U.S. Pat. Nos. 5,196,476, 5,268,418 and 7,759,423.

It is evident that the macromers of the present invention differ fromthe macromers described by these references, and thus result instructurally different preformed stabilizers.

The polymer polyols of the present invention comprise the in-situ,free-radical polymerization product of (A) a base polyol, (B) acomponent selected from the group consisting of (1) a macromer asdescribed herein and (2) a preformed stabilizer as described herein, and(C) one or more ethylenically unsaturated monomers in the presence of(D) at least one free-radical initiator, and optionally, (E) a polymercontrol agent, and the process for the preparation of polymer polyolscomprises free-radically polymerizing these components. The resultantpolymer polyols exhibit high solids contents, i.e., from 20 to 70% byweight, based on the total weight of the resultant polymer polyol. Ingeneral, the solids content of the polymer polyols may typically be atleast about 20% by weight, or at least about 30% by weight, or at leastabout 40% by weight. Typically, the solids content of the polymerpolyols will also typically be about 70% by weight or less, or about 60%by weight or less, or about 55% by weight or less. In general, thesepolymer polyols may have a solids content ranging between anycombination of these upper and lower values, inclusive, such as, forexample, from 20 to 70% by weight, or from about 30 to 60% by weight orfrom about 40 to 55% by weight. These polymer polyols also exhibit goodviscosities, i.e. from about 1000 to about 15,000 mPa·s. In general,these polymer polyols may have viscosities of at least about 1000 mPa·s,or at least about 4000 mPa·s. The polymer polyols may also haveviscosities of about 15,000 mPa·s or less, or about 10,000 mPa·s orless. In general, the polymer polyols may have viscosities rangingbetween any combination of these upper and lower values, inclusive, suchas, for example, from 1000 to 15,000 mPa·s, or from 4,000 to 10,000mPa·s. Polymer polyols of the present invention also typically have goodfilterability.

Suitable base polyols (A) for this aspect of the present inventioninclude, for example, base polyols such as, for example, polyetherpolyols. Suitable polyether polyols include those having a functionalityof at least about 2, or at least about 3. The functionality of suitablepolyether polyols is less than or equal to about 8, or less than orequal to about 6. The suitable polyether polyols may also havefunctionalities ranging between any combination of these upper and lowervalues, inclusive, such as, for example at least about 2 to about 8, orat least about 3 to about 6. The OH numbers of suitable polyetherpolyols is at least about 10 mg KOH/g polyol, preferably at least about15 mg KOH/g polyol, and most preferably at least about 20 mg KOH/gpolyol. Polyether polyols typically also have OH numbers of less than orequal to about 180 mg KOH/g polyol, preferably less than or equal toabout 100 mg KOH/g polyol, and most preferably less than or equal toabout 70 mg KOH/g polyol. The suitable polyether polyols may also haveOH numbers ranging between any combination of these upper and lowervalues, inclusive, such as, for example, at least 10 mg KOH/g polyol toabout 180 mg KOH/g polyol or less, or at least about 15 mg KOH/g polyolto about 100 mg KOH/g polyol or less, or at least about 20 mg KOH/gpolyol to about 70 mg KOH/g polyol or less. The (number average)molecular weight of suitable polyether polyols is typically at leastabout 600 Da, or at least about 2,000 Da or at least about 3,000 Da.Polyether polyols typically have (number average) molecular weights ofless than or equal to 15,000 Da, or less than or equal to 12,000 Da, orless than or equal to 8,000 Da. The suitable polyether polyols may alsohave (number average) molecular weights ranging between any combinationof these upper and lower values, inclusive, such as, for example, atleast about 600 Da to about 15,000 Da or less, or at least about 2000 Dato about 12,000 Da or less, or at least about 3000 Da to about 8000 Daor less.

Examples of such compounds include polyoxyethylene glycols, triols,tetrols and higher functionality polyols, polyoxypropylene glycols,triols, tetrols and higher functionality polyols, mixtures thereof, etc.When mixtures as used, the ethylene oxide and propylene oxide may beadded simultaneously or sequentially to provide internal blocks,terminal blocks or random distribution of the oxyethylene groups and/oroxypropylene groups in the polyether polyol. Suitable starters orinitiators for these compounds include, for example, ethylene glycol,propylene glycol, diethylene glycol, dipropylene glycol, tripropyleneglycol, trimethyolpropane, glycerol, pentaerythritol, sorbitol, sucrose,ethylenediamine, toluene diamine, etc. By alkoxylation of the starter, asuitable polyether polyol for the base polyol component can be formed.

Other suitable base polyols for the present invention include alkyleneoxide adducts of non-reducing sugars and sugar derivatives, alkyleneoxide adducts of phosphorus and polyphosphorus acids, alkylene oxideadducts of polyphenols, polyols prepared from natural oils such as, forexample, castor oil, etc., and alkylene oxide adducts ofpolyhydroxyalkanes other than those described above.

Illustrative alkylene oxide adducts of polyhydroxyalkanes include, forexample, alkylene oxide adducts of 1,3-dihydroxypropane,1,3-di-hydroxybutane, 1,4-dihydroxybutane, 1,4-, 1,5- and1,6-dihydroxyhexane, 1,2-, 1,3-, 1,4-1,6- and 1,8-dihydroxyoctant,1,10-dihydroxydecane, glycerol, 1,2,4-tirhydroxybutane,1,2,6-trihydroxyhexane, 1,1,1-trimethyl-olethane,1,1,1-trimethylolpropane, pentaerythritol, caprolactone,polycaprolactone, xylitol, arabitol, sorbitol, mannitol, and the like.

Other polyols which can be employed include the alkylene oxide adductsof non-reducing sugars, wherein the alkoxides have from 2 to 4 carbonatoms. Non-reducing sugars and sugar derivatives include sucrose, alkylglycosides such as methyl glycoside, ethyl glucoside, etc. glycolglucosides such as ethylene glycol glycoside, propylene glycolglucoside, glycerol glucoside, 1,2,6-hexanetriol glucoside, etc. as wellas alkylene oxide adducts of the alkyl glycosides as disclosed in U.S.Pat. No. 3,073,788, the disclosure of which is herein incorporated byreference.

Other suitable polyols include the polyphenols and preferably thealkylene oxide adducts thereof wherein the alkylene oxides have from 2to 4 carbon atoms. Among the polyphenols which are suitable include, forexample bisphenol A, bisphenol F, condensation products of phenol andformaldehyde, the novolac resins, condensation products of variousphenolic compounds and acrolein, including the1,1,3-tris(hydroxy-phenyl)propanes, condensation products of variousphenolic compounds and glyoxal, glutaraldehyde, other dialdehydes,including the 1,1,2,2-tetrakis (hydroxyphenol)ethanes, etc.

The alkylene oxide adducts of phosphorus and polyphosphorus acid arealso useful polyols. These include ethylene oxide, 1,2-epoxy-propane,the epoxybutanes, 3-chloro-1,2-epoxypropane, etc. as preferred alkyleneoxides. Phosphoric acid, phosphorus acid, the polyphosphoric acids suchas, tripolyphosphoric acid, the polymetaphosphoric acids, etc. aredesirable for use herein.

Suitable components for (B) are selected from the group consisting of(1) macromers as described herein and (2) preformed stabilizers asdescribed herein above.

The (C) ethylenically unsaturated monomers suitable for the polymerpolyols of the present invention and the process of preparing theseinclude those ethylenically unsaturated monomers described above withrespect to the preparation of the preformed stabilizer. Other suitablemonomers include, for example, aliphatic conjugated dienes such asbutadiene and isoprene; monovinylidene aromatic monomers such asstyrene, α-methyl-styrene, (t-butyl)styrene, chlorostyrene, cyanostyreneand bromostyrene; α,β-ethylenically unsaturated carboxylic acids andesters thereof such as acrylic acid, methacrylic acid, methylmethacrylate, ethyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate,itaconic acid, maleic anhydride and the like; α,β-ethylenicallyunsaturated nitriles and amides such as acrylonitrile,methacrylonitrile, acrylamide, methacrylamide, N,N-dimethyl acrylamide,N-(dimethylaminomethyl)acrylamide and the like; vinyl esters such asvinyl acetate; vinyl ethers, vinyl ketones, vinyl and vinylidene halidesas well as a wide variety of other ethylenically unsaturated materialswhich are copolymerizable with the aforementioned monomeric adduct orreactive monomer. It is understood that mixtures of two or more of theaforementioned monomers are also suitably employed in making thepreformed stabilizer. Of the above monomers, the monovinylidene aromaticmonomers, particularly styrene, and the ethylenically unsaturatednitriles, particularly acrylonitrile, are preferred. In accordance withthis aspect of the present invention, it is preferred that theseethylenically unsaturated monomers include styrene and its derivatives,acrylonitrile, methyl acrylate, methyl methacrylate, vinylidenechloride, with styrene and acrylonitrile being particularly preferredmonomers.

It is preferred styrene and acrylonitrile are used in sufficient amountssuch that the weight ratio of styrene to acrylonitrile (S:AN) may isfrom about 80:20 to 20:80, more preferably from about 75:25 to 25:75.These ratios are suitable for polymer polyols and the processes ofpreparing them, regardless of whether they comprise the ethylenicallyunsaturated macromers or the preformed stabilizers of the presentinvention.

Overall, the quantity of ethylenically unsaturated monomer(s) present inthe polymer polyols comprising a preformed stabilizer is at least about20% by weight, based on 100% by weight of the polymer polyol. In anembodiment, the solids content is from about 20 to about 70% by weight.Typically, the solids contents of polymer polyols comprising a preformedstabilizer may range between any combination of these upper and lowervalues, inclusive, such as, for example, from about 20 to about 70% byweight, or from about 30 to about 60% by weight, or from about 40 toabout 55% by weight.

Overall, the quantity of ethylenically unsaturated monomer(s) present inthe polymer polyols comprising the macromers of the present invention isat least about 20% by weight, based on 100% by weight of the polymerpolyol. In an embodiment, the solids content ranges from about 20 toabout 70% by weight.

Suitable free-radical initiators include those as described previouslyfor the preparation of the preformed stabilizers. Among the usefulinitiators are those catalysts having a satisfactory half-life withinthe temperature ranges used in forming the stabilizer, i.e. thehalf-life should be about 25% or less of the residence time in thereactor at any given time. Preferred initiators for this portion of theinvention include acyl peroxides such as didecanoyl peroxide anddilauroyl peroxide, alkyl peroxides such as t-butylperoxy-2-ethylhexanoate, 1,1-di(t-butylperoxy)cyclohexane,1,1-di(t-amylperoxy)cyclohexane, t-butyl peroxypivalate, t-amylperoctoate, t-amylperoxypivalate, 2,5-dimethyl-hexane-2,5-di-per-2-ethylhexoate, t-butyl perneodecanoate, t-butylperbenzoate and1,1-dimethyl-3-hydroxybutyl peroxy-2-ethyl hexanoate, and azo catalystssuch as azobis(isobutyro-nitrile), 2,2′-azobis-(2-methoxylbutyronitrile), and mixtures thereof. Most preferred arethe acyl peroxides described above and the azo catalysts.

The quantity of initiator used herein is not critical and can be variedwithin wide limits. In general, the amount of initiator ranges fromabout 0.01 to 2% by weight, based on 100% by weight of the final polymerpolyol. Increases in catalyst concentration result in increases inmonomer conversion up to a certain point, but past this, furtherincreases do not result in substantial increases in conversion. Theparticular catalyst concentration selected will usually be an optimumvalue, taking all factors into consideration including costs.

Suitable polymer control agents include, for example, one or more monolwhich is typically an alcohol containing at least one carbon atom, suchas methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec.-butanol,t-butanol, n-pentanol, 2-pentanol, 3-pentanol, allyl alcohol, and thelike, and mixtures of the same. The preferred monol is isopropanol.Other known polymer control agents include compounds such as, forexample, ethylbenzene and toluene. In accordance with the presentinvention, the most preferred polymer control agents includeisopropanol, ethanol, tert-butanol, toluene, ethylbenzene, etc.

Polymer control agents can be used in substantially pure form (i.e. ascommercially available) or can be recovered in crude form from thepolymer polyol process and reused as-is. For instance, if the polymercontrol agent is isopropanol, it can be recovered from the polymerpolyol process and used at any point in a subsequent product campaign inwhich the isopropanol is present (i.e. such as the production of PFS Aand PFS B in Table 1 of U.S. Pat. No. 7,179,882, the disclosure of whichis hereby incorporated by reference). The amount of crude polymercontrol agent in the total polymer control agent can range anywhere from0% up to 100% by weight.

Polymer polyols comprising the preformed stabilizers of the presentinvention are prepared by utilizing the processes as disclosed in, forexample, U.S. Pat. Nos. 4,148,840, 4,242,249, 4,954,561, 4,745,153,5,494,957, 5,990,185, 6,455,603, 4,327,005, 4,334,049, 4,997,857,5,196,476, 5,268,418, 5,854,386, 5,990,232, 6,013,731, 5,554,662,5,594,066, 5,814,699 and 5,854,358, the disclosures of which are hereinincorporated by reference. As described therein, a low monomer to polyolratio is maintained throughout the reaction mixture during the process.This is achieved by employing conditions that provide rapid conversionof monomer to polymer. In practice, a low monomer to polyol ratio ismaintained, in the case of semi-batch and continuous operation, bycontrol of the temperature and mixing conditions and, in the case ofsemi-batch operation, also by slowly adding the monomers to the polyol.

In the process of preparing polymer polyols, the temperature range isnot critical, and may vary from about 100° C. to about 140° C. orperhaps greater, the preferred range being from 115° C. to 125° C. Ashas been noted herein, the catalyst and temperature should be selectedsuch that the catalyst has a reasonable rate of decomposition withrespect to the hold-up time in the reactor for a continuous flow reactoror the feed time for a semi-batch reactor.

The mixing conditions employed are those obtained using a back-mixer(e.g., a stirred flask or stirred autoclave). The reactors of this typekeep the reaction mixture relatively homogeneous and so preventlocalized high monomer to polyol ratios such as occur in tubularreactors when such reactors are operated with all the monomer added tothe beginning of the reactor. In addition, more efficient mixing can beobtained by the use of an external pump around loop on the reactorsection. For instance, a stream of reactor contents may be removed fromthe reactor bottom via external piping and returned to the top of thereactor (or vice versa) in order to enhance internal mixing of thecomponents. This external loop may contain a heat exchanger if desired.

The utilization of the processes as described in U.S. Pat. Nos.5,196,476 and 5,268,418 are preferred in this aspect of the presentinvention since these allow for the preparation of polymer polyols witha wide range of monomer compositions, polymer contents and polymerpolyols that could not be otherwise prepared with the necessaryrequisite stability. However, whether the utilization of the processesdisclosed in U.S. Pat. Nos. 5,916,476 and 5,268,418 are essentialdepends on whether the process parameters are such that a satisfactorypolymer polyol can be prepared without using either of these processes.

The polymer polyols of the present invention comprise dispersions inwhich the polymer particles (the same being either individual particlesor agglomerates of individual particles) are relatively small in sizeand, in the preferred embodiment, are all essentially less than aboutone to three microns. However, when high contents of styrene are used,the particles will tend to be larger; but the resulting polymer polyolsare higher useful, particularly when the end use application requires aslittle scorch as possible. In the preferred embodiment, essentially allof the product (i.e., about 99% or more) will pass through the filteremployed in the filtration hindrance (filterability) test that will bedescribed in conjunction with the Examples, This insures that thepolymer polyol products can be successfully processed in all types ofthe relatively sophisticated machine systems now in use for large volumeproduction of polyurethane products, including those employingimpingement-type mixing which necessitate the use of filters that cannottolerate any significant amount of relatively large particles. Lessrigorous applications are satisfied when about 50% of the product passesthrough the filter. Some applications may also find useful products inwhich only about 20% or even less passes through the filter.Accordingly, the polymer polyols of the present invention desirablycontemplate the products in which only 20% pass through the filter,preferably at least 50%, and most preferably, at least 95%.

In accordance with the present invention, the stabilizer is present inan amount sufficient to insure that satisfactory stabilization willresult in the desired filtration hindrance, centrifugible solids leveland viscosity. In this regard, the quantity of preformed stabilizergenerally ranges from about 1 to about 20% by weight, based on the totalfeed. In general, the quantity of preformed stabilizer may range betweenany combination of these upper and lower values, inclusive, such as, forexample, from about 1 to about 20% by weight, of from about 2 to about15% by weight, based on the total feed. As one skilled in the art knowsand understands, various factors including, for example, thefree-radical initiator, the solids content, the weight ratio of S:AN,process conditions, etc., will affect the optimum quantity of preformedstabilizer.

Should it be desirable not to use a preformed stabilizer, then themacromer can be utilized in the polymer polyol process at any levelbetween 0.5% and 30%, based on the total weight of the polymer polyol.The macromer is typically used in the polymer polyol process in anamount of at least about 0.5%, or at least about 1%, or at least about2% by weight The macromer is also typically used in the polymer polyolprocess in an amount of about 30% by weight or less, or of about 20% byweight or less, or of about 15% by weight or less. In general, theamount of macromer used in the polymer polyol process can range betweenany combination of these upper and lower values, inclusive, such as, forexample, from about 0.5% to about 30% by weight, or from about 1% toabout 20% by weight, or from about 2% to about 15% by weight.

Polyurethanes, preferably polyurethane foams, comprising the in-situformed polymer polyols and processes for the production of these polymerpolyols are also part of the present invention. Suitable in-situ formedpolymer polyols for these polyurethanes may be either those prepareddirectly from the inventive macromers, or those prepared from preformedstabilizers which are based on the inventive macromers. Thesepolyurethanes comprise the reaction product of a polyisocyanatecomponent or prepolymer thereof, with an isocyanate-reactive componentcomprising the polymer polyols of the invention. The processes forpreparing these polyurethanes comprise reacting a polyisocyanatecomponent or prepolymer thereof, with an isocyanate-reactive componentcomprising the polymer polyols of the present invention.

In another aspect of the present invention, flexible polyurethane foamscomprise the reaction product of a polyisocyanate component, with anisocyanate-reactive component which comprises the novel in-situ formedpolymer polyols described herein, in the presence of one or morecatalysts, one or more blowing agents, and optionally, one or moresurfactants. In addition, the isocyanate-reactive component mayadditionally comprise one or more crosslinking agents, one or more chainextenders, and/or one or more polyether polyols containing a highethylene oxide content. It is also possible that the isocyanate-reactivecomponent additionally comprises one or more polyoxyalkylene polyols,polyether polyols, polyester polyols, polycarbonate ether polyols,polythioethers, polycarbonates, polyacetals, etc., and mixtures thereof.Various additives and/or auxiliary agents which are known to be usefulin preparing foams may also be present.

The process of preparing the flexible polyurethane foams comprisesreacting (I) a polyisocyanate component, with (II) anisocyanate-reactive component comprising the novel polymer polyolsdescribed herein, in the presence of (III) one or more catalysts, (IV)one or more blowing agents and, optionally, (V) one or more surfactants.In addition, crosslinking agents, chain extenders, otherisocyanate-reactive components, etc., as described herein above, as wellas various other additives and auxiliary agents may also be present.

Suitable polyisocyanates for (I) the polyisocyanate component comprisethose known in the art, to be suitable for the preparation of flexiblepolyurethane foams. The polyisocyanates may be di- or poly-functional,and include, for example, (cyclo)aliphatic di- and/or polyisocyanates,aromatic di- and/or polyisocyanates, and araliphatic di- and/orpolyisocyanates. Some specific examples of suitable aromaticpolyisocyanates and aromatic diisocyanates include compounds such astoluene diisocyanate, diphenylmethane diisocyanate, polymethylenepolyphenyl polyisocyanate, etc., and mixtures or blends thereof.

Suitable compounds to be used as component (II), the isocyanate-reactivecomponent, herein for the preparation of flexible polyurethane foamsinclude the novel in-situ formed polymer polyols described herein. Inaccordance with the present invention, the isocyanate-reactive component(II) may additionally comprise a conventional (i.e. non-solidscontaining) isocyanate-reactive component such as, for example, apolyoxyalkylene polyol, a polyether polyol, a polyester polyol, apolythioether, a polyacetal, a polycarbonate, a polycarbonate etherpolyol, etc., and mixtures thereof. These isocyanate-reactive compoundshaving a functionality of from 2 to 8, or from 2 to 6, or from 2 to 4,and a (number average) molecular weight of from 1000 Da to 12,000 Da, orfrom 1000 Da to 8,000 Da, or from 2000 Da to 6000 Da. In addition, lowermolecular weight isocyanate-reactive components such as crosslinkersand/or chain extenders may be used. These lower molecular weightisocyanate-reactive components include chain extenders which may havefunctionalities of 2 and (number average) molecular weights ranging from61 Da to 500 Da; and crosslinking agents which may have functionalitiesof 3 to 4 and (number average) molecular weights ranging from 92 Da toless than 1000 Da, or from 92 Da to less than or equal to 750 Da.Examples of suitable chain extenders include ethylene glycol,2-methyl-1,3-propanediol, 1,2- and 1,3-propanediol, 1,3- and 1,4- and2,3-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol,dipropylene glycol, etc., and mixtures thereof, and alkylene oxideadducts thereof. Some examples of suitable crosslinking agents includeglycerol, trimethylolpropane, pentaerythritol, diethanolamine,triethanolamine, etc., mixtures thereof, and alkylene oxide adductsthereof. It is also possible to use a polyether polyol that contains ahigh ethylene oxide content.

At least one polyurethane catalyst is required to catalyze the reactionsof the monol, polyols and water with the polyisocyanate. It is common touse an organoamine and/or an organotin compound for this purpose.Suitable polyurethane catalysts are well known in the art; an extensivelist appears in U.S. Pat. No. 5,011,908, the disclosure of which isherein incorporated by reference. Suitable organotin catalysts includetin salts and dialkyltin salts of carboxylic acids. Examples includestannous octoate, dibutyltin dilaurate, dibutyltin diacetate, stannousoleate, and the like. Suitable organoamine catalysts are tertiary aminessuch as trimethylamine, triethylamine, triethylenediamine,bis(2,2′-dimethylamino)ethyl ether, N-ethylmorpholine,diethylenetriamine, and the like. Preferred catalysts are aminecatalysts such as, for example, bis(dimethylaminoethyl)ether indipropylene glycol and triethylene diamine in dipropylene glycol. Theseare commercially available as Niax A-1 and Niax A-33, respectively.

The polyurethane catalysts are typically used in an amount within therange of about 0.05 to about 3 parts, or from about 0.1 to about 2parts, per 100 parts of isocyanate-reactive mixture.

Suitable (III) blowing agents for the present invention include, forexample chemical blowing agents and/or physical blowing agents. Someexamples of the suitable blowing agents for the present inventioninclude water, formic acid, carbon dioxide, chlorofluorocarbons, highlyfluorinated and/or perfluorinated hydrocarbons, chlorinatedhydrocarbons, aliphatic and/or cycloaliphatic hydrocarbons such aspropane, butane, pentane, hexane, etc., or acetals such as methylal,etc. It is possible to use a mixture of blowing agent in the presentinvention. When using a physical blowing agent, this is typically addedto the isocyanate-reactive component of the system. These can, however,also be added in the polyisocyanate component or to a combination ofboth the isocyanate-reactive component and to the polyisocyanatecomponent. Blowing agents may also be used in the form of an emulsion ofthe isocyanate-reactive component. Combinations of water and one or moreauxiliary blowing agents are also suitable herein. In addition, watermay be used as the sole blowing agent.

The amount of blowing agent or blowing agent mixture used may rangebetween any combination of these upper and lower limits, inclusive, suchas, for example, from 0.5 to 20% by weight, or from 0.75 to 10% byweight, based in each case on the total weight of the component (B).When water is the blowing agent, it is typically present in an amount offrom 0.5 to 10% by weight, or from 0.75 to 7% by weight, based on thetotal weight of the component (B). The addition of water can be effectedin combination with the use of the other blowing agents described.

Surfactants are preferably used to prepare the foams. Surfactants areknown help to stabilize the foam until it cures. Suitable surfactantsfor the invention are those well known in the polyurethane industry. Awide variety of organosilicone surfactants are commercially available.Examples of suitable surfactants include DC-5043, DC-5164 and DC-5169,as well as Niax L-620, a product of Momentive Performance Materials, andTegostab B8244, a product of Evonik-Goldschmidt. Many other siliconesurfactants known to those in the art may be substituted for thesesuitable silicones. The amount of surfactant may range between anycombination of upper and lower limits inclusive, such as, for example,of about 0.1 to 4, or about 0.2 to 3, parts per 100 parts ofisocyanate-reactive mixture.

Other optional components that may be present in the flexible foamformulations include, for example, flame retardants, antioxidants,pigments, dyes, liquid and solid fillers, etc. Such commercial additivesare included in the foams in conventional amounts when used.

The flexible foams are prepared using methods that are well known in theindustry. These methods may include continuous or discontinuousfree-rise slabstock foam processes and molded foam processes. In atypical slabstock process, the isocyanate is continuously mixed togetherwith the other formulation chemicals by passing through a mixing headand then into a trough which overflows onto a moving conveyor.Alternatively, the reacting mixture is deposited directly onto themoving conveyor. In another embodiment, high pressure liquid carbondioxide is fed into one or more of the formulation components, typicallythe polyol, entering into the mixing head and the resin blend is passedthrough a frothing device where the pressure is let down and theresultant froth is deposited onto the conveyor. The foam expands andrises as it moves down the conveyor to form a continuous foam slab thatis cut into blocks or buns of the desired length for curing and storage.After curing for one or more days, these foam buns can be cut into thedesired shapes for the end-use applications. In the discontinuousprocess, the reactants are quickly mixed together through a head or in alarge mixing chamber. The reaction mixture is then deposited into alarge box or other suitable container where foam expansion occurs toform a bun of the lateral dimensions of the container.

A typical molded foam process usually employs a one-shot approach inwhich a specific amount of the isocyanate stream (the “A” side) israpidly combined and mixed with a specific amount of the remainingformulation components (the “B” side). An additional stream may beemployed to bring in one or more specific components not included withthe “B” side stream. The mixture is quickly deposited into a mold thatis then closed. The foam expands to fill the mold and produce a partwith the shape and dimensions of the mold.

In accordance with the present invention, the flexible foams areprepared at isocyanate indices ranges from 70 to 130, or from 80 to 120or from 90 to 110. The term “isocyanate index”, which may also bereferred to as the NCO index, is defined herein as the ratio of reactiveisocyanate groups (equivalents) to active hydrogen groups (equivalents),multiplied by 100%.

Although less preferred, a prepolymer approach to making the foams canalso be used. In this approach, a significant portion of theisocyanate-reactive mixture is reacted with the polyisocyanate, and theresulting prepolymer is then reacted with the remaining components.

In a first embodiment, the invention is directed to a macromercomprising the reaction product of (a) a polyether dithiocarbonatepolyol having an equivalent weight of 230 Da to 5600 Da, andfunctionality of 1 to 8, having a dithiocarbonate content of from 0.05%to 20% by weight, and which comprises the copolymerization product of areaction mixture comprising (i) one or more starter polyether polyolshaving an equivalent weight less than 1000 Da, an OH number greater than56 mg KOH/g polyol, and functionality of 1 to 8, (ii) an alkylene oxide,and (iii) carbon disulfide, in the presence of (iv) an alkoxylationcatalyst; with optionally, (b) an ethylenically unsaturated compoundcontaining hydroxyl reactive groups; optionally, in the presence of (c)a catalyst.

In a second embodiment, the invention is directed to the macromeraccording to the first embodiment in which (a) the polyetherdithiocarbonate polyol has an equivalent weight of 280 Da to 5400 Da, afunctionality of 2 to 7, a dithiocarbonate content of 0.10 to 15% byweight, and comprises the reaction product of (i) one or more starterpolyether polyols having an OH number of at least 112 mg KOH/g polyol to1850 mg KOH/g polyol, and a functionality of 2 to 7; (ii) the alkyleneoxide comprises ethylene oxide and/or propylene oxide; and (iv) thealkoxylation catalyst comprises a double metal cyanide complex catalyst.

In a third embodiment, the invention is directed to the macromeraccording to the first or second embodiments in which (b) theethylenically unsaturated compound containing hydroxyl reactive groupscomprises methyl methacrylate, ethyl methacrylate, maleic anhydride,3-isopropenyl-α,α-dimethyl benzyl isocyanate, 2-isocyanatoethylmethacrylate, adducts of isophorone diisocyanate and 2-hydroxyethylmethacrylate, adducts of toluene diisocyanate and 2-hydroxylpropylacrylate, or mixtures thereof.

In a fourth embodiment, the invention is directed to the macromeraccording to one of the first to third embodiments in which the catalyst(c) comprises an organotin catalyst or a bismuth catalyst.

In a fifth embodiment, the invention is directed to a process for thepreparation of a macromer which comprises (I) reacting (a) a polyetherdithiocarbonate polyol having an equivalent weight of 230 Da to 5600 Da,and functionality of 1 to 8, having a dithiocarbonate content of from0.05% to 20% by weight, and which comprises the copolymerization productof a reaction mixture comprising (i) one or more starter polyetherpolyols having an equivalent weight less than 1000 Da, an OH numbergreater than 56 mg KOH/g polyol, and functionality of 1 to 8, (ii) analkylene oxide, and (iii) carbon disulfide, in the presence of (iv) analkoxylation catalyst; with optionally, (b) an ethylenically unsaturatedcompound containing hydroxyl reactive groups; optionally, in thepresence of (c) a catalyst.

In a sixth embodiment, the invention is directed to the process ofpreparing a macromer according to the fifth embodiment in which (a) thepolyether dithiocarbonate polyol has an equivalent weight of 280 Da to5400 Da, a functionality of 2 to 7, a dithiocarbonate content of 0.10 to15% by weight, and comprises the reaction product of (i) one or morestarter polyether polyols having an OH number of at least 112 mg KOH/gpolyol to 1850 mg KOH/g polyol, and a functionality of 2 to 7; (ii) thealkylene oxide comprises ethylene oxide and/or propylene oxide; and (iv)the alkoxylation catalyst comprises a double metal cyanide complexcatalyst.

In a seventh embodiment, the invention is directed to the process ofpreparing the macromer according to the fifth or sixth embodiments inwhich (b) the ethylenically unsaturated compound containing hydroxylreactive groups comprises methyl methacrylate, ethyl methacrylate,maleic anhydride, 3-isopropenyl-α,α-dimethyl benzyl isocyanate,2-isocyanatoethyl methacrylate, adducts of isophorone diisocyanate and2-hydroxyethyl methacrylate, adducts of toluene diisocyanate and2-hydroxylpropyl acrylate, or mixtures thereof.

In an eighth embodiment, the invention is directed to the process ofpreparing the macromer according to one of the fifth to seventhembodiments in which the catalyst (c) comprises an organotin catalyst ora bismuth catalyst.

In a ninth embodiment, the invention is directed to a preformedstabilizer which comprises the free-radical polymerization product of(1) a macromer according to one of the first to fourth embodiments; with(2) at least one ethylenically unsaturated monomer; in the presence of(3) a free-radical polymerization initiator; and, optionally, (4) aliquid diluent; and, optionally, (5) a polymer control agent.

In a tenth embodiment, the invention is directed to the preformedstabilizer according to the ninth embodiment in which (2) theethylenically unsaturated monomer comprises styrene, acrylonitrile, ormixtures thereof.

In a eleventh embodiment, the invention is directed to the preformedstabilizer according to one of the ninth or tenth embodiments in which(3) the free-radical polymerization initiator comprises a peroxideinitiator, an azo initiator or mixtures of peroxide and azo initiators.

In a twelfth embodiment, the invention is directed to the preformedstabilizer according to one of the ninth to eleventh embodiments inwhich (4) the diluent comprises isopropanol, a polyol having an OHnumber of 20 mg KOH/g polyol to 280 mg KOH/g polyol, or a mixture of amonol and a polyol.

In a thirteenth embodiment, the invention is directed to the preformedstabilizer according to one of the ninth to twelfth embodiments in which(5) the polymer control agent comprises isopropanol, toluene, ethylbenzene, dodecylmercaptan, carbon tetrachloride, carbon tetrabromide,chloroform, methylene chloride or a mixture thereof.

In a fourteenth embodiment, the invention is directed to a process forpreparing a preformed stabilizer comprising (A) free-radicallypolymerizing (1) a macromer obtainable by a process according to one ofthe fifth through eighth embodiments; with (2) at least oneethylenically unsaturated monomer; in the presence of (3) a free-radicalpolymerization initiator; and, optionally, (4) a liquid diluent; and,optionally, (5) a polymer control agent.

In an fifteenth embodiment, the invention is directed to the process forpreparing a preformed stabilizer according to the fourteenth embodimentin which (2) the ethylenically unsaturated monomer comprises styrene,acrylonitrile, or mixtures thereof.

In a sixteenth embodiment, the invention is directed to the process forpreparing a preformed stabilizer according to one of the fourteenth orfifteenth embodiments in which (3) the free-radical polymerizationinitiator comprises a peroxide initiator, an azo initiator, or mixturesof peroxide and azo initiators.

In a seventeenth embodiment, the invention is directed to the processfor preparing a preformed stabilizer according to one of the fourteenthto sixteenth embodiments in which (4) the diluent comprises isopropanol,a polyol having an OH number of 20 mg KOH/g polyol to 280 mg KOH/gpolyol, or a mixture of a monol and a polyol.

In a eighteenth embodiment, the invention is directed to the process forpreparing a preformed stabilizer according to one of the fourteenth toseventeenth embodiments in which (5) the polymer control agent comprisesisopropanol, toluene, ethylbenzene, dodecylmercaptan, carbontetrachloride, carbon tetrabromide, chloroform, methylene chloride or amixture thereof.

In a nineteenth embodiment, the invention is directed to a polymerpolyol comprising the in-situ, free-radical polymerization product of(A) a base polyol, (B) a component comprising at least one of: (1) amacromer according to one of the first to fourth embodiments; and (2) apreformed stabilizer according to one of the ninth to thirteenthembodiments; and (C) at least one ethylenically unsaturated monomer; inthe presence of (D) a free-radical polymerization initiator; and,optionally, (E) a polymer control agent.

In a twentieth embodiment, the invention is directed to the polymerpolyol according to the nineteenth embodiment in which the polymerpolyol has a solids content of 20 to 70% by weight.

In a twenty-first embodiment, the invention is directed to the polymerpolyol according one of the nineteenth to twentieth embodiments in which(A) the base polyol has a functionality of 2 to 8 and an OH number of 10mg KOH/g polyol to 180 mg KOH/g polyol.

In a twenty-second embodiment, the invention is directed to the polymerpolyol according to one of the nineteenth to twenty-first embodiments inwhich (C) the ethylenically unsaturated monomer comprises styrene,acrylonitrile, or mixtures thereof.

In a twenty-third embodiment, the invention is directed to the polymerpolyol according to the twenty-second embodiment in which a mixture ofstyrene and acrylonitrile is present in a weight ratio of from 80:20 to20:80.

In a twenty-fourth embodiment, the invention is directed to the polymerpolyol according to one of the nineteenth to twenty-third embodiments inwhich (D) the free-radical initiator comprises a peroxide compound, anazo compound, or mixtures thereof.

In a twenty-fifth embodiment, the invention is directed to a process forpreparing a polymer polyol comprising (I) free-radically polymerizing(A) a base polyol; (B) a compound comprising at least one of: (1) amacromer obtainable by a process according to one of the fifth to eighthembodiments; and (2) a preformed stabilizer obtainable by a processaccording to one of the fourteenth to eighteenth embodiments; and (C) atleast one ethylenically unsaturated monomer; in the presence of (D) afree-radical polymerization initiator; and, optionally, (E) a polymercontrol agent.

In a twenty-sixth embodiment, the invention is directed to the processof preparing a polymer polyol according to the twenty-fifth embodimentin which the polymer polyol has a solids content of 20 to 70% by weight.

In a twenty-seventh embodiment, the invention is directed to the processof preparing a polymer polyol according to one of the twenty-fifth totwenty-sixth embodiments in which (A) the base polyol has afunctionality of 2 to 8 and an OH number of 10 mg KOH/g polyol to 180 mgKOH/g polyol.

In a twenty-eighth embodiment, the invention is directed to the processof preparing a polymer polyol according to one of the twenty-fifth totwenty-seventh embodiments in which (C) the ethylenically unsaturatedmonomer comprises styrene, acrylonitrile, or mixtures thereof.

In a twenty-ninth embodiment, the invention is directed to the processof preparing a polymer polyol according to the twenty-eighth embodimentin which a mixture of styrene and acrylonitrile is present in a weightratio of from 80:20 to 20:80.

In a thirtieth embodiment, the invention is directed to the process ofpreparing a polymer polyol according to one of the twenty-fifth totwenty-ninth embodiments in which (D) the free-radical initiatorcomprises a peroxide compound, an azo compound, or mixtures thereof.

In a thirty-first embodiment, the invention is directed to apolyurethane foam comprising the reaction product (I) a diisocyanateand/or polyisocyanate component, with (II) an isocyanate-reactivecomponent comprising the novel polymer polyol according to one of thenineteenth to twenty-fourth embodiments, in the presence of (III) acatalyst, (IV) a blowing agent, and (V) a surfactant.

In a thirty-second embodiment, the invention is directed to a processfor preparing a polyurethane foam which comprises reacting (I) adiisocyanate and/or polyisocyanate component, with (II) anisocyanate-reactive component comprising the novel polymer polyolobtainable by a process according to one of the twenty-fifth tothirtieth embodiments, in the presence of (Ill) a catalyst, (IV) ablowing agent, and (V) a surfactant.

The following examples further illustrate details for the preparationand use of the compositions of this invention. The invention, which isset forth in the foregoing disclosure, is not to be limited either inspirit or scope by these examples. Those skilled in the art will readilyunderstand that known variations of the conditions and processes of thefollowing preparative procedures can be used to prepare thesecompositions. Unless otherwise noted, all temperatures are degreesCelsius and all parts and percentages are parts by weight andpercentages by weight, respectively.

EXAMPLES

The following components were used in the working examples.

-   Polyol 1: a propylene oxide adduct of sorbitol containing 12%    ethylene oxide with a hydroxyl number of 33 mg KOH/g polyol-   Polyol 2: a propylene oxide adduct of glycerin containing a 20%    ethylene oxide cap with a hydroxyl number of 36 mg KOH/g polyol and    having a viscosity of 820 mPa·s-   Polyol 3: a propylene oxide adduct of glycerin with a hydroxyl    number of 57 mg KOH/g polyol and having a viscosity of 465 mPa·s-   Polyol 4: a glycerin/sorbitol started polyether polyol containing    about 81 to 82% of propylene oxide and about 17 to 18% of ethylene    oxide, having an OH number of about 31.5 mg KOH/g polyol-   Starter Polyol 1 a propylene oxide adduct of sorbitol containing    with a hydroxyl number of 143 mg KOH/g polyol-   Starter Polyol 2 a propylene oxide adduct of sorbitol containing    with a hydroxyl number of 198 mg KOH/g polyol-   CS₂: carbon disulfide, commercially available from SigmaAldrich-   PCA: isopropanol, a polymer control agent-   TMI: isopropenyl dimethyl benzyl isocyanate (an unsaturated    aliphatic isocyanate) which is commercially available as TMI® from    Allnex-   Isocyanate A: a monomeric MDI comprising about 42% by weight of the    4,4′-isomer of MDI, about 57% by weight of the 2,4′-isomer of MDI    and the balance being the 2,2′-isomer of MDI-   Isocyanate B: toluene diisocyanate comprising 80% by weight of the    2,4-isomer and 20% by weight of the 2,6-isomer, and having an NCO    group content of 48.3%-   TBPEH: tertiary-butylperoxy-2-ethylhexanoate-   Initiator A: 2,2′-azobisisobutyronitrile, a free-radical    polymerization initiator commercially available as VAZO 64 from E.I.    Du Pont de Nemours and Co.-   Initiator B: tertiary-amylperoxypivalate, a free radical    polymerization initiator commercially available under the name    Trigonox 125-C75 from AkzoNobel-   Catalyst A: a double metal cyanide catalyst commercially available    from Covestro LLC-   Catalyst B: bismuth neodecanoate, commercially available under the    name CosCat 83 from Vertellus-   Catalyst C: 70% by weight bis[2-dimethylaminoethyl]ether in 30%    dipropylene glycol, an amine catalyst, commercially available from    Momentive Performance Materials as NIAX A-1-   Catalyst D: 33% by weight diazabicyclooctane in 67% by weight    dipropylene glycol, an amine catalyst, commercially available from    Momentive Performance Materials as NIAX A-33-   Surfactant A: a silicon surfactant commercially available as DC5043    from Air Products-   DEOA-LF diethanolamine, a commercially available foam    crosslinker/foam modifier that is commercially available from Air    Products-   Viscosity: dynamic viscosities reported in mPa·s at 25° C.-   Filtration: filterability was determined by diluting one part by    weight sample (e.g. 200 grams) of polymer polyol with two parts by    weight anhydrous isopropanol (e.g. 400 grams) to remove any    viscosity-imposed limitations and using a fixed quantity of material    relative to a fixed cross-sectional area of screen (e.g. 1⅛ in.    diameter or 2.875 cm), such that all of the polymer polyol and    isopropanol solutions passes by gravity through a 700-mesh screen.    The 700-mesh screen is made with a Dutch twill weave. The actual    screen used had a nominal opening of 30 microns. The amount of    sample which passes through the screen within 600 seconds is    reported in percent, a value of 100 percent indicates that over 99    weight percent passes through the screen.

Methods: OH Number (Hydroxyl Number):

The OH numbers were determined according to ASTM D4274-11, and arereported in mg[KOH]/g[polyol].

Viscosity:

Viscosity was conducted on an Anton-Paar SVM 3000 viscometer at 25° C.that has been demonstrated to give equivalent results as can begenerated with ASTM-D4878-15. The instrument was calibrated usingmineral oil reference standards of known viscosity.

Gel Permeation Chromatography:

The number average and weight average, Mn and Mw, respectively,molecular weights were determined by gel-permeation chromatography (GPC)using a method based on DIN 55672-1, employing chloroform as the eluentwith a mixed bed column (Agilent PL Gel; SDVB; 3 micron Pore diameter:1×Mixed-E+5 micron Pore diameter: 2×Mixed-D), refractive index (RI)detection and calibrated with polyethylene glycol as the standard.

¹H-NMR:

The dithiocarbonate content was determined by dissolving the sample indeuterated chloroform and run on a 400 MHz nuclear magnetic resonance(NMR) (a Varian MR400) spectrometer employing high-resolution ¹H-NMR forcharacterization.

Force-to-crush (FTC) was measured on the uncrushed 12 in.×12 in.×4 in.(30.5 cm×30.5 cm×10.2 cm) foam samples using a standard IFD test and 50sq in. (322.6 sq. cm) indentor foot. The foam height was measured bylowering the foot slowly until a resistance of 0.5 lbs. (226.8 g) wasdetected. The foot was next forced into the foam at 20 in./min. (50.8cm/min) to 25% of the measured height (75% compression) and the forceimmediately recorded. The foot was immediately returned to the initialfoam height and a second compression cycle and force measure initiated.This process was repeated a third time to complete the measurement.Thus, three force measurements, 1^(st) cycle (FTC1), 2^(nd) cycle(FTC2), 3^(rd) cycle (FTC3) were obtained on each foam sample. The firstmeasurement provides an indication of how much force is required tocrush the foam initially, whereas the difference between the second(FTC2) and third (FTC3) values indicates how effective the initialcrushing cycle was in opening the foam.

Polyol Preparation: Preparation of Polyol 5:

A polyether polyol composition was prepared using the ingredients andamounts as shown in Table 1. To prepare the polyether polyolcomposition, the 1-L reactor was charged with the starter polyetherpolyol and Catalyst A at ambient temperature. The reactor temperaturewas raised to 130° C. and the starter mixture was de-watered usingvacuum distillation with a slight nitrogen sparge through the startermixture. The reactor was then sealed under vacuum at 130° C. and a ninitial amount of PO was dosed to the reactor equal to 10% by weight ofthe starter polyether. The pressure in the reactor was monitored untilthe pressure dropped 50% indicating the catalyst was active. Once thecatalyst was determined to be active, the reactor temperature waslowered to 100° C. The PO feed was resumed at a rate sufficient tomaintain the reaction pressure below 35 psig. When ˜71% of the totalweight of PO had been fed, the CS₂ feed was begun at a rate ˜60% of thePO rate. Once the desired amount of CS₂ was fed, the PO feed wascontinued until the total amount of PO was fed. After completion of thePO addition, the reaction mixture was vacuum stripped at 130° C. to givePolyol 5 with a OH # of 33.7, a viscosity of 8091 mPa·s, and 1.3 wt. %CS₂ (as measured by NMR).

TABLE 1 Polyol 5 Starter Final OH# Final Polyol 1 Catalyst A PO CS₂ (mgKOH/g Viscosity (g) (g) (g) (g) polyol) (mPa · s) 168 0.1404 553 30.033.7 8091

Preparation of Polyol 6:

A polyether polyol composition was prepared using the ingredients andamounts listed in Table 2. To prepare the polyether polyol composition,the 20 kg reactor was charged with the starter polyether polyol andCatalyst A at ambient temperature. The reactor temperature was raised to130° C. and the starter mixture was de-watered using vacuum distillationwith a slight nitrogen sparge through the starter mixture. The reactortemperature was lowered to 100° C. and the re actor was sealed undervacuum. An initial amount of PO was dosed to the reactor equal to 10% byweight of the starter polyether. The pressure in the reactor wasmonitored until the pressure dropped 50% indicating the catalyst wasactive. The PO and EO feed was begun at a rate sufficient to maintainthe reaction pressure below 10 psig. When ˜71% of the total weight of POhad been fed, the EO feed was stopped and the CS₂ feed was begun at arate ˜55% of the PO rate. Once the desired amount of CS₂ was fed, the POfeed was continued until the total amount of PO was fed. Aftercompletion of the PO addition, the reaction mixture was vacuum strippedat 130° C. The reactor was cooled to 90° C. and the reactor was chargedwith 7.2 g Irganox 1076 and agitated for 30 minutes to give Polyol 6with a OH # of 32.6, a viscosity of 4413 mPa·s, and 2.5 wt % CS₂ (asmeasured by NMR).

TABLE 2 Polyol 6 Starter Final Final Polyol 2 Catalyst EO CS₂ OH# (mgViscosity (g) A (g) (g) PO (g) (g) KOH/g polyol) (mPa · s) 2914 4.322165 12240 722 32.6 4413

Macromer Preparation:

-   Macromer A: prepared by heating a blend comprising 61% by weight of    Polyol 1 and 39% by weight of Polyol 5, Isocyanate A (0.2 wt. %),    and Catalyst B (100 ppm) at 75° C. for 2 hour s. Calculated carbon    disulfide content=0.6% by weight.-   Macromer B: Polyol 6-   Macromer C: prepared by heating a blend comprising 65% by weight of    Polyol 1 and 35% by weight of Polyol 6, Isocyanate A (0.2 wt. %),    and Catalyst B (100 ppm) at 75° C. for 2 hour s. Carbon disulfide    content=0.9% by weight.-   Macromer D: a blend of 65% of Polyol 1 and 35% by weight of    Polyol 6. Calculated carbon disulfide content=0.9% by weight.-   Macromer E: prepared by heating Polyol 1 with TMI (0.6 wt. % by    weight), Isocyanate A (0.2 wt. % by weight), and Catalyst B (100    ppm) at 75° C. for 4 hours.-   Macromer F: a blend of 90% by weight of Macromer C and 10% by weight    of Macromer E. Calculated carbon disulfide content=0.8% by weight.

Preformed Stabilizer (PFS) Preparation:

The preformed stabilizer was prepared in a two-stage reaction systemcomprising a continuously-stirred tank reactor (CSTR) fitted with animpeller and 4 baffles (first-stage) and a plug-flow reactor (secondstage). The residence time in each reactor was about 60 minutes. Thereactants were pumped continuously to the reactor from feed tanksthrough an in-line static mixer and then through a feed tube into thereactor, which was well mixed. The temperature of the reaction mixturewas controlled at 120±5° C. The product from the second-stage reactoroverflowed continuously through a pressure regulator designed to controlthe pressure in each stage at 65 psig. The product, i.e. the preformedstabilizer, then passed through a cooler and into a collection vessel.The preformed stabilizer formulation is disclosed in Table 3.

Preformed stabilizers A-F were prepared from Macromers A-F,respectively, using the following formulation:

TABLE 3 Preformed Stabilizer Composition Component PFS PCA typeIsopropanol PCA, wt. % 60.0% Macromer, wt. % 24.0% Monomer, wt. % 15.9%Styrene/acrylonitrile weight ratio 50:50 TBPEH, wt. %  0.1%

Polymer Polyol Preparation:

This series of examples (Table 4) relates to the preparation of polymerpolyols. The polymer polyols were prepared in a two-stage reactionsystem comprising a continuously-stirred tank reactor (CSTR) fitted withan impeller and 4 baffles (first-stage) and a plug-flow reactor (secondstage). The residence time in each reactor was about 60 minutes. Thereactants were pumped continuously from feed tanks through an in-linestatic mixer and then through a feed tube into the reactor, which waswell mixed. The temperature of the reaction mixture was controlled at115±5° C. The product from the second-stage reactor overflowedcontinuously through a pressure regulator designed to control thepressure in each stage at 45 psig. The product, i.e. the polymer polyol,then passed through a cooler and into a collection vessel. The crudeproduct was vacuum stripped to remove volatiles. The wt. % total solidsin the product was calculated from the concentrations of residualmonomers measured in the crude polymer polyol before stripping.

TABLE 4 FORMULATIONS FOR POLYMER POLYOLS Example PMPO 1 PMPO 2 PMPO 3PMPO 4 PMPO 5 Polyol 2 2 2 2 2 Polyol (wt. % in fed) 54.2 49.4 49.4 54.249.4 Macromer B (wt. % in feed) 0 0 0 0 0 PFS A B B C D PFS (wt. % infeed) 8.3 8.3 8.3 8.3 8.3 Styrene (wt. % in feed) 23.6 26.6 26.6 23.626.6 Acrylonitrile (wt. % in feed) 13.6 15.4 15.4 13.6 15.4 Initiator BB A B B Initiator (wt/% in feed) 0.25 0.25 0.29. 0.25 0.25 PCA (wt. % infeed) 5.3 4.7 5.0 5.1 4.8 Total Solids (wt. %) 39.8 44.6 44.7 39.8 44.8Viscosity (mPa · s at 250) 5242 8946 13468 6122 7231 Filterability 700mesh (%) 100 100 29% 100 100 Mean Particle Size (microns) 1.7 2.2 2.42.5 2.0 Example PMPO 6 PMPO 7 PMPO 8 PMPO 9* PMPO 10 Polyol 2 2 2 2 3Polyol (wt. % in fed) 49.4 49.4 48.4 49.4 74.0 Macromer B (wt. % infeed) 0 0 1.0 0 2 PFS D F E E PFS (wt. % in feed) 8.3 8.3 8.3 8.3 0Styrene (wt. % in feed) 26.6 26.6 26.6 26.6 10.3 Acrylonitrile (wt. % infeed) 15.4 15.4 15.4 15.4 13.4 Initiator A B B B B Initiator (wt/% infeed) 0.29 0.29 0.25 0.25 0.32 PCA (wt. % in feed) 5.0 5.0 5.0 4.6 0Total Solids (wt. %) 44.7 44.6 45.0 44.5 23.0 Viscosity (mPa · s at 250)14607 5861 5784 6339 1545 Filterability 700 mesh (%) 235 100 100 100 100Mean Particle Size (microns) 2.8 1.6 0.9 1.2 2.1 *Comparative example

General Procedure for Making Foams:

The foams in Table 5 were prepared by mixing the polyol, the surfactant,water, catalysts, and diethanolamine in a flask to create a masterblend. Then, the desired amount of polymer polyol was added to a cupcontaining the desired amount of master blend. The contents of the cupwere mixed for 55 seconds. The desired amount of Isocyanate componentnecessary to give an isocyanate index of 100 was added to the cupcontaining the master blend and polymer polyol mixture. The contents ofthe cup were mixed together for 5 seconds, and the reacting mixture wasquickly poured into a 150° F. (65.5(C) water-jacketed mold. After 4.5minutes, the foam was removed from the mold, run through a cell-openingcrushing device, and then placed in a 250° F. (121.1° C.) oven for 30minutes to post cure. After 24 hours of aging in a controlledtemperature and humidity laboratory, the foams were submitted forphysical property testing. As can be seen in Table 5, the foam preparedfrom the inventive PMPO (Foam 2) had improved % Settle andForce-To-Crush values.

TABLE 5 Foam Formulations and Physical Properties Foam 1* Foam 2 PMPOtype PMPO 9 PMPO 5 PMPO, pphp 50 50 Polyol 4, pphp 50 50 WATER, pphp 3 3DEOA-LF, pphp 1.73 1.73 Surfactant A, pphp 0.5 0.5 Catalyst D, pphp 0.240.24 Catalyst C, pphp 0.1 0.1 Isocyanate B, pphp 39.28 39.28 INDEX 100100 Foam Properties % Settle 3.6 2.6 FTC1 280 300 FTC2 88 97 FTC3 50 60*Comparative Example ** pphp: parts per hundred parts

Although the invention has been described in detail in the foregoing forthe purpose of illustration, it is to be understood that such detail issolely for that purpose and that variations can be made therein by thoseskilled in the art without departing from the spirit and scope of theinvention except as it may be limited by the claims.

1. A macromer comprising the reaction product of: (a) a polyetherdithiocarbonate polyol having an equivalent weight of 230 Da to 5600 Da,and functionality of 1 to 8, having a dithiocarbonate content of from0.05% to 20% by weight, and which comprises the copolymerization productof a reaction mixture comprising (i) one or more starter polyetherpolyols having an equivalent weight less than 1000 Da, an OH numbergreater than 56 mg KOH/g polyol, and functionality of 1 to 8, (ii) analkylene oxide, and (iii) carbon disulfide, in the presence of (iv) analkoxylation catalyst; with (b) an ethylenically unsaturated compoundcontaining hydroxyl reactive groups; optionally, in the presence of (c)at least one catalyst.
 2. The macromer according to claim 1, wherein (a)said polyether dithiocarbonate polyol has an equivalent weight of 280 Dato 5400 Da, a functionality of 2 to 7, a dithiocarbonate content of 0.10to 15% by weight, and comprises the reaction product of (i) one or morestarter polyether polyols having an OH number of at least 112 mg KOH/gpolyol to 1850 mg KOH/g polyol, and a functionality of 2 to 7; (ii) saidalkylene oxide comprises ethylene oxide and/or propylene oxide; and (iv)said alkoxylation catalyst comprises a double metal cyanide complexcatalyst.
 3. The macromer according to claim 1, wherein (b) saidethylenically unsaturated compound containing hydroxyl reactive groupscomprises methyl methacrylate, ethyl methacrylate, maleic anhydride,3-isopropenyl-α,α-dimethyl benzyl isocyanate, 2-isocyanatoethylmethacrylate, adducts of isophorone diisocyanate and 2-hydroxyethylmethacrylate, adducts of toluene diisocyanate and 2-hydroxylpropylacrylate, or mixtures thereof.
 4. The macromer according to claim 1,wherein said catalyst (c) comprises an organotin catalyst or a bismuthcatalyst.
 5. A process for the preparation of a macromer comprising: (1)reacting: (a) a polyether dithiocarbonate polyol having an equivalentweight of 230 Da to 5600 Da, and functionality of 1 to 8, having adithiocarbonate content of from 0.05% to 20% by weight, and whichcomprises the copolymerization product of a reaction mixture comprising(i) one or more starter polyether polyols having an equivalent weightless than 1000 Da, an OH number greater than 56 mg KOH/g polyol, andfunctionality of 1 to 8, (ii) an alkylene oxide, and (iii) carbondisulfide, in the presence of (iv) an alkoxylation catalyst; with (b) anethylenically unsaturated compound containing hydroxyl reactive groups;optionally, in the presence of: (c) at least one catalyst.
 6. Theprocess according to claim 5, wherein (a) said polyether dithiocarbonatepolyol has an equivalent weight of 280 Da to 5400 Da, a functionality of2 to 7, a dithiocarbonate content of 0.10 to 15% by weight, andcomprises the reaction product of (i) one or more starter polyetherpolyols having an OH number of at least 112 mg KOH/g polyol to 1850 mgKOH/g polyol, and a functionality of 2 to 7; (ii) said alkylene oxidecomprises ethylene oxide and/or propylene oxide; and (iv) saidalkoxylation catalyst comprises a double metal cyanide complex catalyst.7. The process according to claim 5, wherein (b) said ethylenicallyunsaturated compound containing hydroxyl reactive groups comprisesmethyl methacrylate, ethyl methacrylate, maleic anhydride,3-isopropenyl-α,α-dimethyl benzyl isocyanate, 2-isocyanatoethylmethacrylate, adducts of isophorone diisocyanate and 2-hydroxyethylmethacrylate, adducts of toluene diisocyanate and 2-hydroxylpropylacrylate, or mixtures thereof.
 8. The process according to claim 5,wherein said catalyst (c) comprises an organotin catalyst or a bismuthcatalyst.
 9. A preformed stabilizer comprising the free-radicalpolymerization product of: (1) a macromer which comprises the reactionproduct of (a) a polyether dithiocarbonate polyol having an equivalentweight of 230 Da to 5600 Da, and functionality of 1 to 8, having adithiocarbonate content of 0.05% to 20% by weight, and which comprisesthe copolymerization product of a reaction mixture comprising (i) one ormore starter polyether polyols having an equivalent weight less than1000 Da, an OH number greater than 56 mg KOH/g polyol, and functionalityof 1 to 8, (ii) an alkylene oxide, with (iii) carbon disulfide, in thepresence of (iv) an alkoxylation catalyst; optionally, with (b) anethylenically unsaturated compound containing hydroxyl reactive groups;optionally, in the presence of (c) a catalyst; with (2) at least oneethylenically unsaturated monomer; in the presence of (3) a free-radicalpolymerization initiator; and, optionally, (4) a liquid diluent; and,optionally, (5) a polymer control agent.
 10. The preformed stabilizeraccording to claim 9, wherein (1)(a) said polyether dithiocarbonatepolyol has an equivalent weight of 280 Da to 5400 Da, a functionality of2 to 7, a dithiocarbonate content of 0.10 to 15% by weight, andcomprises the reaction product of (i) one or more starter polyetherpolyols having an OH number of at least 112 mg KOH/g polyol to 1850 mgKOH/g polyol, and a functionality of 2 to 7; (ii) said alkylene oxidecomprises ethylene oxide and/or propylene oxide; and (iv) saidalkoxylation catalyst comprises a double metal cyanide complex catalyst.11. The preformed stabilizer according to claim 9, wherein (1)(b) saidethylenically unsaturated compound containing hydroxyl reactive groupscomprises methyl methacrylate, ethyl methacrylate, maleic anhydride,3-isopropenyl-α,α-dimethyl benzyl isocyanate, 2-isocyanatoethylmethacrylate, adducts of isophorone diisocyanate and 2-hydroxyethylmethacrylate, adducts of toluene diisocyanate and 2-hydroxylpropylacrylate, or mixtures thereof.
 12. The preformed stabilizer according toclaim 9, wherein said catalyst (c) comprises an organotin catalyst or abismuth catalyst.
 13. A process for preparing a preformed stabilizercomprising: (A) free-radically polymerizing (1) a macromer whichcomprises the reaction product of: (a) a polyether dithiocarbonatepolyol having an equivalent weight of 230 Da to 5600 Da, andfunctionality of 1 to 8, having a dithiocarbonate content of 0.05% to20% by weight, and which comprises the copolymerization product of areaction mixture comprising (i) one or more starting polyether polyolhaving an equivalent weight less than 1000 Da, an OH number greater than56 mg KOH/g polyol, and a functionality of 1 to 8, (ii) an alkyleneoxide, and (iii) carbon disulfide, in the presence of (iv) analkoxylation catalyst; optionally, with (b) an ethylenically unsaturatedcompound containing hydroxyl reactive groups; optionally, in thepresence of (c) a catalyst; with (2) at least one ethylenicallyunsaturated monomer; in the presence of (3) a free-radicalpolymerization initiator; and, optionally, (4) a liquid diluent; and,optionally, (5) a polymer control agent.
 14. The process according toclaim 13, wherein (1)(a) said polyether dithiocarbonate polyol has anequivalent weight of 280 Da to 5400 Da, a functionality of 2 to 7, adithiocarbonate content of 0.10 to 15% by weight, and comprises thereaction product of (i) one or more starter polyether polyols having anOH number of at least 112 mg KOH/g polyol to 1850 mg KOH/g polyol, and afunctionality of 2 to 7; (ii) said alkylene oxide comprises ethyleneoxide and/or propylene oxide; and (iv) said alkoxylation catalystcomprises a double metal cyanide complex catalyst.
 15. The processaccording to claim 13, wherein (1)(b) said ethylenically unsaturatedcompound containing hydroxyl reactive groups comprises methylmethacrylate, ethyl methacrylate, maleic anhydride,3-isopropenyl-α,α-dimethyl benzyl isocyanate, 2-isocyanatoethylmethacrylate, adducts of isophorone diisocyanate and 2-hydroxyethylmethacrylate, adducts of toluene diisocyanate and 2-hydroxylpropylacrylate, or mixtures thereof.
 16. The process according to claim 13,wherein said catalyst (c) comprises an organotin catalyst or a bismuthcatalyst.
 17. A polymer polyol comprising the in-situ, free-radicalpolymerization product of: (A) a base polyol; (B) a component comprisingat least one of: (1) a macromer containing dithiocarbonate functionalitythat comprises the reaction product of: (a) a polyether dithiocarbonatepolyol having an equivalent weight of 230 Da to 5600 Da, andfunctionality of 1 to 8, having a dithiocarbonate content of from 0.05%to 20% by weight, and which comprises the copolymerization product of areaction mixture comprising (i) one or more starter polyether polyolshaving an equivalent weight less than 1000 Da, an OH number greater than56 mg KOH/g polyol, and a functionality of 1 to 8, (ii) an alkyleneoxide, and (iii) carbon disulfide, in the presence of (iv) analkoxylation catalyst; optionally, with (b) an ethylenically unsaturatedcompound containing hydroxyl reactive groups; optionally, in thepresence of (c) a catalyst; and (2) a preformed stabilizer thatcomprises the free-radical polymerization product of: (1) a macromerwhich comprises the reaction product of: (a) a polyether dithiocarbonatepolyol having an equivalent weight of 230 Da to 5600 Da, andfunctionality of 1 to 8, having a dithiocarbonate content of 0.05% to20% by weight, and which comprises the copolymerization product of areaction mixture comprising (i) one or more starter polyether polyolshaving an equivalent weight less than 1000 Da, an OH number greater than56 mg KOH/g polyol, and a functionality of 1 to 8, (ii) an alkyleneoxide, and (iii) carbon disulfide, in the presence of (iv) analkoxylation catalyst; with, optionally, (b) an ethylenicallyunsaturated compound containing hydroxyl reactive groups; optionally, inthe presence of (c) a catalyst; with (2) at least one ethylenicallyunsaturated monomer, in the presence of (3) a free-radicalpolymerization initiator, and, optionally, (4) a liquid diluent, and,optionally (5) a polymer control agent; and (C) at least oneethylenically unsaturated monomer; in the presence of (D) a free-radicalpolymerization initiator; and, optionally, (E) a polymer control agent.18. A process of preparing the polymer polyol of claim 17, comprising(I) free-radically polymerizing: (A) a base polyol; (B) a componentcomprising at least one of: (1) a macromer containing dithiocarbonatefunctionality that comprises the reaction product of: (a) a polyetherdithiocarbonate polyol having an equivalent weight of 230 Da to 5600 Da,and functionality of 1 to 8, having a dithiocarbonate content of from0.05% to 20% by weight, and which comprises the copolymerization productof a reaction mixture comprising (i) one or more starter polyetherpolyols having an equivalent weight less than 1000 Da, an OH numbergreater than 56 mg KOH/g polyol, and a functionality of 1 to 8, (ii) analkylene oxide, and (iii) carbon disulfide, in the presence of (iv) analkoxylation catalyst; optionally, with (b) an ethylenically unsaturatedcompound containing hydroxyl reactive groups; optionally, in thepresence of (c) a catalyst; and (2) a preformed stabilizer thatcomprises the free-radical polymerization product of: (1) a macromerwhich comprises the reaction product of: (a) a polyether dithiocarbonatepolyol having an equivalent weight of 230 Da to 5600 Da, andfunctionality of 1 to 8, having a dithiocarbonate content of 0.05% to20% by weight, and which comprises the copolymerization product of areaction mixture comprising (i) one or more starter polyether polyolshaving an equivalent weight less than 1000 Da, an OH number greater than56 mg KOH/g polyol, and a functionality of 1 to 8, (ii) an alkyleneoxide, and (iii) carbon disulfide, in the presence of (iv) analkoxylation catalyst; with, optionally, (b) an ethylenicallyunsaturated compound containing hydroxyl reactive groups; optionally, inthe presence of (c) a catalyst; with (2) at least one ethylenicallyunsaturated monomer, in the presence of (3) a free-radicalpolymerization initiator, and, optionally, (4) a liquid diluent, and,optionally (5) a polymer control agent; and (C) at least oneethylenically unsaturated monomer, in the presence of (D) a onefree-radical polymerization initiator, and, optionally, (E) a polymercontrol agent.
 19. A polyurethane foam comprising the reaction productof: (I) a diisocyanate or polyisocyanate component, with (II) anisocyanate-reactive component comprising the polymer polyol of claim 17,in the presence of (Ill) a catalyst, (IV) a blowing agent, and (V) asurfactant.
 20. A process for preparing a polyurethane foam, comprisingreacting: (I) a diisocyanate or polyisocyanate component, with (II) anisocyanate-reactive component comprising the polymer polyol of claim 17,in the presence of: (III) a catalyst, (IV) a blowing agent, and (V) asurfactant.